OPINION OF THE COURT
Appellant Deri H. Maurer (“Maurer”) pleaded guilty to a single count information charging him with possession of child pornography in violation of 18 U.S.C. § 2252A(a)(5)(B). The District Court imposed a sentence of sixty months of imprisonment and a five-year term of supervised release, which included special conditions restricting internet access and association with minors. On appeal, Maurer challenges the procedural reasonableness of his sentence as well as the special conditions of his supervised release. For the reasons that follow, we will affirm.
*75 I. BACKGROUND
Maurer came to the attention of authorities on July 7, 2009, after sending an email via an online social networking website to a fictitious eighteen-year-old teenager, (“Nate”), whose internet profile was created by undercover law enforcement officers to investigate crimes involving sexual exploitation of children. In the email, Maurer solicited the exchange of nude images and asked “Nate” how old he was. The following day, Maurer sent another email again inquiring about nude pictures and reiterating his interest in “young guys too your age and under,” and stating “hope your into older men.” (Presentence Report (“PSR”) ¶ 10.) Three images, which depicted a nude older man exposing himself, were attached to this email. Thereafter, Maurer sent another email directing “Nate” to a website featuring pictures and videos of Maurer performing sexual acts.
In response to a request transmitted by authorities through “Nate,” on or about July 13, 2009, Maurer mailed two compact disks (“CDs”) to a provided address. The package containing the CDs included a handwritten note from Maurer describing the contents of the CDs, soliciting the trade of additional images, and expressing the desire to “meet and have some good fun together.” (Id. ¶ 16.) Upon inspection, law enforcement officers confirmed that the CDs contained numerous images and videos of child pornography. Based upon this information, the investigating officers obtained a search warrant to search and seize computers and videos from Maurer’s residence.
On July 23, 2009, law enforcement officers executed a search of Maurer’s residence pursuant to the warrant. Maurer admitted to authorities that he had sent the CDs to “Nate,” that he had been viewing and collecting child pornography for six months, and that there was additional child pornography on his computer as well as a library of CDs in his bedroom closet. He denied having any sexual contact with minors. In total, law enforcement officers seized from Maurer’s residence forty image files and nineteen video files containing child pornography. An examination of these files revealed that several depicted adult males penetrating and otherwise sexually abusing prepubescent children, some of whom were bound with rope and tape. (Id. ¶¶ 17, 20, 23.)
On February 2, 2010, Maurer pleaded guilty, pursuant to a written plea agreement, to a one-count information alleging that he possessed child pornography in violation of 18 U.S.C. § 2252A(a)(5)(B). At his plea hearing, Maurer admitted that he “knowingly possessed].... more than 600 images of child pornography,” 1 some of which depicted “individuals who were clearly minors that had not attained the age of 12 ... engaging in sexually explicit conduct with other minors and adults.” (Joint Appendix (“J.A.”) at 36-37.) Maurer additionally admitted that “possession of these images involve[d] the use of a computer.” (Id. at 36.) These admissions were mirrored in the plea agreement, which also contained a waiver of Maurer’s right to appeal the District Court’s acceptance of the stipulations contained therein and an acknowledgment that the District Court was not bound by them. (Id. at 22, 26.)
The District Court held a sentencing hearing on June 28, 2010. According to the PSR prepared by the United States *76 Probation Office, Maurer’s total offense level under the Sentencing Guidelines was 28, and his criminal history category was I, yielding an advisory Guidelines range of 78 to 97 months of imprisonment. Notably, the Probation Office found that Maurer’s offense involved material that portrayed “sadistic or other violent conduct,” and therefore recommended application of a four level enhancement set forth in U.S.S.G. § 2G2.2(b)(4). (PSR ¶ 23.) The Probation Office relied on dictionary definitions of these terms to determine the applicability of this four level enhancement. (Id. ¶23 n.2.) Although Maurer stipulated to conduct providing the basis for sentencing enhancements relating to his use of a computer and possession of images depicting prepubescent minors, he did not stipulate to possession of images depicting sadistic or violent conduct. Pri- or to sentencing, Maurer objected to the application of § 2G2.2(b)(4) recommended in the PSR, contending that “the material described in paragraph 23 is [injsufficient for the enhancement to apply nor does it seem to meet the definitions provided in footnote 2 of the report.” (Id. Addendum.)
During his sentencing hearing, Maurer presented arguments against the application of § 2G2.2(b)(4) and requested a downward variance based on the factors set forth in 18 U.S.C. § 3553(a). The District Court denied Maurer’s objection to the four level enhancement authorized by § 2G2.2(b)(4), stating that “[wjithout question I think that’s an enhancement that is applicable and has been appropriately applied.” (J.A. at 67.) The District Court further explained, “I do think that [the enhancement] is appropriately applied ... because to indicate that children being essentially molested, raped and tortured is not sadistic or somehow masochistic, I think it strains credibility to make that argument---- [a]nd this case is certainly no different, given the videos that were involved, the photos that were involved.” (Id.) The District Court then proceeded to calculate Maurer’s total offense level as 28 and his criminal history category as I, yielding a Guidelines sentence range of 78 to 97 months, consistent with the PSR. Upon considering Maurer’s arguments pertaining to the sentencing objectives set forth in § 3553(a), the District Court granted a downward variance and sentenced Maurer to sixty months of imprisonment, followed by a five-year term of supervised release.
The District Court included several special conditions as part of Maurer’s five-year term of supervised release. Only two are relevant to this appeal: (1) a prohibition on “possessfing], procuring], purchasing], or otherwise obtaining] access to any form of computer network, bulletin board, Internet, or exchange format involving computers unless specifically approved by the U.S. Probation Office,” with disputes regarding applicability “to be decided by the court”; and (2) a prohibition on “having any contact with children of either sex, under the age of 18, without the expressed approval of the U.S. Probation Office ... [and from] obtaining] employment or performing] volunteer work which includes, as part of its job/work description, contact with minor children without the expressed approval of the U.S. Probation Office.” (J.A. at 5, 72.) The District Court did not explain the factual basis for imposing these conditions. (Id. at 72.) Maurer did not object to the length of his supervised release term or any of the accompanying special conditions specified by the District Court.
A timely appeal followed.
II. JURISDICTION AND STANDARD OF REVIEW
The District Court exercised jurisdiction pursuant to 18 U.S.C. § 3231, and we have jurisdiction pursuant to 18 U.S.C. § 3742 and 28 U.S.C. § 1291.
*77
We review sentences for both procedural and substantive reasonableness under an abuse of discretion standard.
United States v. Merced,
We also review a district court’s decision to impose a special condition of supervised release under the abuse of discretion standard.
United States v. Freeman,
III. DISCUSSION
A. Application of U.S.S.G. § 2G2.2(b)(4) 2
Maurer contends that the District Court abused its discretion by applying U.S.S.G. § 2G2.2(b)(4) because: (1) the enhancement itself is vague and overly broad, evinced by the fact that the Probation Office had to reference a dictionary to determine whether the enhancement applied; (2) the photographs at issue are not “sadistic” or “violent” according to the ordinary meaning of those terms; and (3) the Government and Probation Office never established that he intended to receive the images or that he derived pleasure from viewing them. Maurer also challenges application of the enhancement by arguing that the District Court failed to give due regard to the written plea agreement. None of these arguments are persuasive.
In our view, § 2G2.2(b)(4) is not vague or overly broad, and it clearly encompasses the images and videos Maurer possessed. Under § 2G2.2(b)(4), “[i]f the offense involved material that portrays sadistic or masochistic conduct or other depictions of violence,” a defendant’s offense level is increased by four levels. U.S.S.G. § 2G2.2(b)(4). Although the Sentencing Guidelines do not define “sadistic or masochistic conduct” or “depictions of violence,” we believe that the ordinary meaning of these terms provides courts with sufficient guidance to ensure that the enhancement is appropriately applied to specific and identifiable conduct.
3
See Perrin v. United States,
Webster’s Dictionary defines “sadism” as “the infliction of pain ... as a means of obtaining sexual release,” “delight in physical or mental cruelty,” and “excessive cruelty.” Webster’s Third New International Dictionary (unabridged) 1997-98 (1993). “Masochism,” on the other hand, is defined as obtaining “sexual gratification through the acceptance of physical abuse or humiliation.”
Id.
at 1388. “Violence” is defined primarily as the “exertion of any physical force so as to injure or abuse.”
Id.
at 2554. Although violence, in isolation, can be interpreted broadly, its use here immediately follows the more narrow and specific terms “sadistic or masochistic conduct,” and thus we are compelled to construe its meaning narrowly.
See CSX Transp., Inc. v. Alabama Dept. of Revenue,
- U.S. -,
*79
After considering the ordinary meaning of these terms, we join other circuits in holding that the application of § 2G2.2(b)(4) is appropriate where an image depicts sexual activity involving a prepubescent minor that would have caused pain to the minor.
5
We believe that this approach is consistent with the meaning of § 2G2.2(b)(4) and that it provides a sufficiently narrow basis on which sentencing courts may determine whether the enhancement applies. Moreover, in light of our interpretation of § 2G2.2(b)(4), we hold that in order to apply this enhancement, a sentencing court need only find, by a preponderance of the evidence, that an image depicts sexual activity involving a prepubescent minor and that the depicted activity would have caused pain to the minor.
See United States v. Freeman,
Additionally, contrary to Maurer’s claim, there is no need for the sentencing court to determine whether a defendant intended to possess the images or actually derived pleasure from viewing them. Section 2G2.2(b)(4) is applied on the basis of strict liability.
See
U.S.S.G. § 2G2.2(b)(4) Application Note 2 (“Subsection (b)(4) applies if the offense involved material that portrays sadistic or masochistic conduct or other depictions of violence,
regardless of whether the defendant specifically intended
to possess, access with intent to view, receive, or distribute such materials.”) (emphasis added);
United States v. Richardson,
We also note our belief that the application of § 2G2.2(b)(4) is not limited to circumstances where the pain that would result from the depicted conduct is the result of sexual penetration by an adult or bondage of a child.
6
As the Fifth Circuit observed in
Lyckman,
many of the cases involving the application of this enhancement involve “pornographic images depicting bondage or the insertion of foreign objects into the body canals of a child,” but such “images hardly exhaust the malevolent universe of sexual violence against children.”
See
Turning now to the facts of Maurer’s case, we observe that the District *81 Court applied § 2G2.2(b)(4) based upon a correct interpretation of the enhancement provision and after making the required findings articulated above. The District Court explained, “I do think that [the enhancement] is appropriately applied ... because to indicate that children being essentially molested, raped and tortured is not sadistic or somehow masochistic, I think it strains credibility to make that argument____[a]nd this case is certainly no different, given the videos that were involved, the photos that were involved.” (J.A. at 67.) The images and videos the court referred to included the following depictions: “a prepubescent ... male ... anally penetrated by an older male”; “a prepubescent ... female with her wrist bound to her ankle with duct tape”; and an image of “a prepubescent ... female, her legs bound above her head with white rope, with an object inserted between her legs.” (PSR ¶¶ 17, 23.) Although the District Court did not explicitly state that these sexual acts would cause pain, it is clear from the District Court’s references to “rape,” “torture,” and “children,” and its statement that “this case is certainly no different,” that it believed the depicted acts would have caused the children pain. Thus, the District Court’s decision to apply the four level enhancement under § 2G2.2(b)(4) was supported by the required findings we articulated above— namely, that the images Maurer possessed depicted sexual activity involving a prepubescent minor that would have caused the child to experience pain. Moreover, the District Court’s conclusion that these acts fit within the meaning of “sadistic” rested on a sound interpretation of the enhancement. Without dwelling further on the horrid acts depicted within the pictures and videos Maurer possessed, we will simply express our belief that it does indeed “strainf] credibility” to argue that these actions are not “sadistic” within the ordinary meaning of that term. Accordingly, the District Court did not misinterpret the meaning of the enhancement, commit a procedural error, or otherwise abuse its discretion in applying § 2G2.2(b)(4) based on the facts of Maurer’s offense. Therefore, we hold that the District Court properly applied the four level enhancement.
We also find no merit in Maurer’s contention that the court abused its discretion by accepting the plea agreement and then making additional factual findings beyond those factual stipulations provided within it. The agreement itself explicitly states that “[t]his agreement to stipulate ... cannot and does not bind the sentencing judge, who may make independent factual findings and may reject any or all of the stipulations entered into by the parties.” (J.A. at 22.) Moreover, we have previously held that “[a] sentencing court is not bound by factual stipulations in a plea agreement and has discretion to make factual findings based on other relevant information.”
United States v. Ketcham,
*82 Finally, the record clearly demonstrates that the District Court meaningfully considered Maurer’s sentencing arguments, weighed the sentencing factors set forth in 18 U.S.C. § 3553(a), and sentenced Maurer to a term of imprisonment that was reasonable in light of his offense.
B. Special Conditions of Supervised Release
Maurer also challenges two of the special conditions imposed by the District Court as part of his five-year term of supervised release. As previously explained, these special conditions prohibited Maurer: (1) from “possess[ing], procuring], purchasing], or otherwise obtaining] access to any form of computer network, bulletin board, Internet, or exchange format involving computers unless specifically approved by the U.S. Probation Office,” with disputes regarding applicability “to be decided by the court”
8
; and (2) “from having any contact with children of either sex, under the age of 18, without the expressed approval of the U.S. Probation Office ... [and from] obtaining] employment or performing] volunteer work which includes, as part of its job/work description, contact with minor children without the expressed approval of the U.S. Probation Office.” (J.A. at 5.) Maurer contends that the limitation on internet use is unduly restrictive given that he neither contacted a minor for sex nor had a prior record of doing so. Maurer similarly argues that the prohibition on contact with minors is unsupported by the facts underlying his offense of conviction and that the condition amounts to an excessive delegation of authority to the Office of Probation. Because Maurer did not object to the District Court’s imposition of these special conditions at the sentencing hearing, we review for plain error.
9
Heckman,
Although sentencing judges have broad discretion in fashioning special conditions of supervised release, this discretion is not without limit.
Id.
at 405. Sentencing courts must exercise this discretion within the parameters of 18 U.S.C. § 3583, which requires that any special conditions be “reasonably related” to the factors set forth in 18 U.S.C. § 3553(a).
10
18 U.S.C. § 3583(a)-(d).
*83
Moreover, any such condition must impose “no greater deprivation of liberty than is reasonably necessary” to deter future criminal conduct, protect the public, and rehabilitate the defendant. 18 U.S.C. § 3583(d)(2);
see United States v. Pruden,
B.l. Special Condition Restricting Internet Access
We have previously identified several key considerations when addressing challenges to special conditions restricting internet and computer use. In
United States v. Heckman,
we explained that “three factors [] have guided our prior holdings in this area: (1) the
length
and (2)
coverage
of the imposed ban; and, (3) the defendant’s underlying
conduct.”
Maurer argues that the circumstances of his offense, when considered in light of the factors highlighted above and compared to other cases in our circuit dealing with similar challenges, require that we vacate the special condition restricting his use of the internet. In support of this position, Maurer places considerable emphasis on the fact that his use of the internet did not involve sexual exploitation of an individual who was actually a minor. Indeed, as noted above, the presence or absence of such conduct has been an important factor in previous decisions of this Court wherein we considered the reasonableness of restrictions on internet and computer use.
See Miller, 594
F.3d at 187. For example, in
United States v.
*84
Crandon,
we upheld a three-year ban on internet use because the defendant “used the Internet as a means to develop an illegal sexual relationship with a young girl.”
Contrary to Maurer’s position, however, our consideration of this factor as well as its underlying concerns actually militate in favor of upholding the restriction on his use of the internet. Although Maurer did not in this particular instance use the internet to exploit a person that was actually a minor, his use of the internet nonetheless triggers concerns of predation that we believe are sufficient to sustain the restriction at issue here. While “Nate” was, insofar as Maurer knew, eighteen years old and therefore not a minor, Maurer explicitly stated via an internet message that he was interested in “young guys too your age
and under.”
(PSR ¶ 10 (emphasis added).) Moreover, Maurer was clearly willing to use the internet to facilitate a sexual encounter. He directed “Nate” to a website featuring images of himself engaging in sexual acts and later expressed a desire “to meet and have some good fun together.”
(Id.
¶ 16.) These facts, when viewed together, demonstrate that Maurer’s use of the internet went beyond simply obtaining child pornography. Maurer’s expressed interest in minors, when coupled with his demonstrated willingness to use the internet as a means for arranging sexual encounters, presents a tangible risk to children. This risk exists notwithstanding the fact that “Nate” was eighteen years old insofar as Maurer knew at the time. Thus, although Maurer did not actually use the internet to seek out a minor in this particular instance, we believe that the unique facts of his offense trigger the very concerns that animated our consideration of the solicitation and predation concerns highlighted in
Miller. See
We also believe that the duration and scope of the restriction on internet use are reasonable. While there is no precise formula for determining what constitutes a reasonable length of time, five years falls comfortably within the range of time periods we have previously upheld.
See, e.g., Thielemann,
The restriction on internet use therefore shares a nexus to the goals of deterrence and protection of the public and does not involve a greater deprivation of liberty than is necessary in this case. Accordingly, the District Court did not plainly err in imposing this condition.
B.2. Special Condition Restricting Association with Minors
We also reject Maurer’s contention that the restriction on contact with minors is overly broad and amounts to an excessive delegation of authority to the Office of Probation. As discussed above, in the course of a conversation with “Nate” wherein Maurer ultimately suggested meeting for a sexual encounter, Maurer stated that he had a sexual interest in minors. Moreover, his substantial collection of child pornography contained a number of images that depicted sadistic and violent sexual abuse of prepubescent children. These facts, taken together, suggest that Maurer is a risk to children, and therefore the District Court did not plainly err in restricting his contact with minors, regardless of the fact that he was convicted only for possession of child pornography.
See United, States v. Loy,
Finally, we do not believe that this restriction, which permits the Probation Office to approve exceptions, amounts to an excessive delegation of authority. “Probation officers have broad statutory authority to advise and supervise probationers, and to ‘perform any other duty that the court may designate.’ ”
Pruden,
Maurer points us to our decisions in
Heckman
and
Voelker
in arguing that the condition restricting his contact with minors is an improper delegation of authority. Both of these cases, however, are distinguishable. In
Heckman,
we vacated a condition of supervised release which required the defendant to “follow the directions of the United States Probation Office regarding any contact with children
*86
of either sex under the age of 18.”
In
Voelker,
we vacated as an “unbridled delegation of authority” a condition with specific terms that more closely resemble the terms of the condition imposed in Maurer’s case.
13
Whereas the condition at issue in Voelker infringed upon the relationship with the defendant’s own children, Maurer’s condition is of more limited effect given his age and circumstances. Each of Maurer’s children is an adult. Thus, the restriction on association with minors does not trigger the concern that animated our determination in Voelker. Moreover, whereas the condition in Voelker was of lifetime duration, the condition at issue here lasts only five years. Absent the unique concerns present in Voelker, we do not find that the condition restricting Maurer’s association with children amounts to an excessive delegation of authority.
IV. CONCLUSION
For the reasons stated above, we will affirm Maurer’s sentence and the two challenged special conditions of supervised release.
Notes
. For purposes of determining the number of images, each video or similar visual depiction is equivalent to 75 images of child pornography. U.S.S.G. § 2G2.2 cmt. n.4 (B)(ii). Maurer admitted to possessing more than 600 images based on the application of this conversion formula.
. Section 2G2.2(b)(4) was previously identified within the Guidelines as § 2G2.2(b)(3). The present designation came into effect on November 1, 2004. U.S.S.G. Supp.App. C, amend. 664 (2010). For consistency and clarity, throughout this opinion we have replaced references to subsection "(3)” within quoted excerpts of other opinions with "( [4])-”
. To date, we have not spoken precedentially on the meaning of "sadistic,” “masochistic,” and “violent” as used within § 2G2.2(b)(4), or otherwise precisely determined what type of depictions warrant application of the four-level enhancement provided for in this Guidelines provision. In
United States v. Parmelee,
we suggested that images depicting sexual abuse and bondage of children should have compelled a district court to apply the four level enhancement, yet we did not elaborate
*78
further on the actual meaning of the terms within § 2G2.2(b)(4) or the general circumstances under which the enhancement should apply.
See
. Maurer couches his argument that § 2G2.2(b)(4) is vague and overbroad in general terms, contending simply that these defects render a sentencing court’s application of this provision an abuse of discretion. Nowhere in his appellate brief does he claim that these alleged defects render § 2G2.2(b)(4) unconstitutionally vague. To the extent that Maurer’s argument can be construed as a claim of unconstitutional vagueness, we similarly reject this claim.
Given the clarity of the enhancement when interpreted according to the ordinary meaning of its terms, we are confident that the provision does not fail to give a person of ordinary intelligence fair notice of the conduct to which it applies.
See United States v. Jones,
Additionally, Maurer cannot show vagueness in light of the facts of his specific case.
See United States v. Mazurie,
.
See United States v. Rodgers,
. This position is consistent with precedent in other circuits. For example, the Seventh Circuit determined that § 2G2.2(b)(4) applies not only to "acts likely to cause physical pain,” but also to "sexual gratification which is purposefully degrading and humiliating, [and] conduct which causes mental suffering or psychological or emotional injury in the victim.”
Rodgers,
. We note that in the plea agreement, the Government never agreed to recommend a specific Guidelines range, nor did it provide any assurance that it would advocate for a sentence within the range yielded by the factual stipulations set forth in the agreement. Furthermore, the plea agreement explicitly provided: “The sentencing judge may impose any reasonable sentence up to and including the statutory maximum term of imprisonment. ... This Office cannot and does not make any representation or promise as to what guideline range may be found by the sentencing judge, or as to what sentence Deri *82 H. Maurer ultimately will receive.” (J.A. at 20.) In light of this and other provisions, Maurer is hard pressed to argue that the District Court's acceptance of the agreement gave rise to an obligation that it sentence him within a range limited by the factual stipulations set forth therein.
. Hereinafter we will refer generally to this condition as a restriction on "internet” use. Notably, the condition at issue here is distinct from and more narrow than a restriction on "computer” use, which would bar a defendant from accessing both computers and the internet.
. We use a four-prong analysis to determine whether the district court committed plain error. An appellant must show: (1) an error was committed; (2) the error was plain; (3) the error affected the defendant's substantial rights; and (4) the error "seriously affects the fairness, integrity, or public reputation of judicial proceedings.”
United States v. Olano,
. Those factors include: “(1) the nature and circumstances of the offense and the history and characteristics of the defendant; [and] (2) the need for the sentence imposed ... (B) to afford adequate deterrence to criminal conduct; (C) to protect the public from further crimes of the defendant; and (D) to provide *83 the defendant with needed educational or vocational training, medical care, or other correctional treatment in the most effective manner.” 18 U.S.C. § 3553(a).
. We
also observe that, "courts of appeals have consistently required district courts to set forth factual findings to justify special probation conditions,”
United States v. Warren,
. Our explanation in
Thielemann
is equally applicable here. Therein, we acknowledged that "[c]omputers and Internet access have become virtually indispensable in the modern world.”
. The condition in
Voelker
read as follows: “The defendant shall not associate with children under the age of 18 except in the presence of a responsible adult who is aware of the defendant’s background and current offense and who has been approved by the probation officer.”
