John K. MacIver Institute for Public Policy, Inc. v. Erpenbach, 848 N.W.2d 862

In March–April 2011 the Institute requested copies of Senator Jon Erpenbach’s correspondence related to 2011 Wis. Act 10; Erpenbach produced documents but redacted sender-identifying information (names, e‑mail addresses).
The Institute narrowed its request to unredacted e‑mails sent from state and local government e‑mail accounts; Erpenbach refused to produce public e‑mail addresses and other identifying information.
Erpenbach justified redactions as protecting senders from threats/harassment, preserving privacy and free‑speech/petition rights, and avoiding a chilling effect; he also invoked Senate custom and practice.
The Institute sued for a writ of mandamus to compel disclosure; the circuit court denied relief, deferring to the senator’s judgment; the Institute appealed.
The court of appeals held the dispute justiciable, concluded the e‑mails are public records, found the redacted sender identifiers were not “purely personal,” and reversed — ordering disclosure and remanding for fees.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Are Erpenbach’s nondisclosure decisions justiciable (or protected as legislative "rules of proceeding")?	Court may review; request does not concern internal legislative procedure.	Senate custom leaves disclosure decisions to individual senators; courts may not review rules of proceedings.	Justiciable — decisions did not implicate Article IV §8 rules of proceeding; courts may decide.
Are the contested e‑mails (including sender names/address) public records?	E‑mails connected to pending legislation and kept on government system are records subject to disclosure.	Sender identifiers are “purely personal” and not connected to official acts.	E‑mails are public records; sender identity and origin are relevant to oversight and not purely personal.
Does the public interest in nondisclosure (harassment, privacy, chilling) outweigh disclosure?	Non‑disclosure protects senders from threats/harassment and prevents chilling of communications.	Disclosure would chill speech and expose citizens to reprisals, especially given charged atmosphere.	Defendant failed to show a reasonable probability of harm; public interest in disclosure prevails under the statutory presumption of openness.
Standard of review — degree of deference to custodian (legislator)?	Senator as elected lawmaker in extraordinary circumstances warrants heightened deference.	—	Court reviews custodian balancing de novo; no special heightened deference for legislators.

Schill v. Wisconsin Rapids Sch. Dist., 327 Wis. 2d 572 (2010) (discusses when personal information within records may be exempt)
Custodian of Records for Legislative Tech. Servs. Bureau v. State, 272 Wis. 2d 208 (2004) (legislative "rules of proceeding" are limited to internal processes for lawmaking)
Doe v. Reed, 561 U.S. 186 (2010) (compelled disclosure of petition signers requires reasonable probability of threats/harassment to overcome disclosure)
Zellner v. Cedarburg Sch. Dist., 300 Wis. 2d 290 (2007) (strong presumption of openness under Wisconsin public records law)
Osborn v. Board of Regents of the Univ. of Wis. Sys., 254 Wis. 2d 266 (2002) (custodian must balance interests; court reviews and may order disclosure)
Hempel v. City of Baraboo, 284 Wis. 2d 162 (2005) (custodian bears burden to justify nondisclosure; factual support strengthens custodian’s position)
Lassa v. Rongstad, 294 Wis. 2d 187 (2006) (first amendment privacy claim requires showing a reasonable probability of harassment)