Limelight Networks, Inc. v. Akamai Technologies, Inc., 134 S. Ct. 2111

Akamai holds an exclusive license to a patent (U.S. No. 6,108,703) claiming a multi-step method for delivering web content via a content delivery network (CDN); one claimed step is "tagging" by which content providers designate content to be cached.
Limelight operates a competing CDN and performs several claimed steps but requires its customers (content providers) to perform the tagging step themselves; Limelight provides instructions/assistance but does not do the tagging.
Akamai sued Limelight for patent infringement; a jury found infringement and awarded damages, but the decision was affected by the Federal Circuit’s Muniauction decision requiring attribution of all method steps to a single party for direct infringement under §271(a).
A Federal Circuit panel held Limelight did not directly infringe because it did not direct or control customers’ tagging; on rehearing en banc the Federal Circuit reversed on inducement grounds, concluding inducement liability under §271(b) can exist even if no single party directly infringed under §271(a).
The Supreme Court granted certiorari on whether inducement liability under §271(b) can be imposed when no one has directly infringed under §271(a), and unanimously reversed the Federal Circuit: inducement requires actual direct infringement by someone.

Issue	Plaintiff's Argument (Akamai)	Defendant's Argument (Limelight)	Held
Whether a defendant can be liable for inducing infringement under 35 U.S.C. §271(b) when no one has directly infringed under §271(a)	Limelight induced infringement by performing some steps and encouraging customers to perform the rest; inducement can be based on encouraging a third party even if no single actor is a direct infringer	Inducement requires predicate direct infringement by someone; Muniauction means no single party performed all steps, so no direct infringement occurred	Reversed Federal Circuit: inducement under §271(b) requires that someone have directly infringed under §271(a) (or another statutory provision); without direct infringement, no inducement liability.

Aro Mfg. Co. v. Convertible Top Replacement Co., 365 U.S. 336 (establishes that inducement/contributory liability is predicated on direct infringement)
Muniauction, Inc. v. Thomson Corp., 532 F.3d 1318 (Fed. Cir. 2008) (held direct infringement requires attribution of all method steps to a single party)
Deepsouth Packing Co. v. Laitram Corp., 406 U.S. 518 (refused to extend contributory liability where direct infringement did not occur)
Global-Tech Appliances, Inc. v. SEB S.A., 563 U.S. 754 (discussed scienter and inducement principles in patent law)
Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17 (each claim element is material to the claimed invention)