Police in Madison, Wisconsin threatened jail time to a good samaritan who warned fellow motorists of an upcoming speed trap on Tuesday. Fred Zahn, who owns Renu Auto Body, stood on the sidewalk of Fish Hatchery Road with a handmade cardboard sign reading, "Speed Trap Ahead." Police intervened as soon as they found themselves unable to issue citations, claiming Zahn could not exercise free speech on "city property." Officials said that he could be charged with obstructing a police officer.

"You should have seen how people slowed down when they saw my sign," Zahn told the Wisconsin State Journal. "(The police) say they're out to slow people down, but you can't tell me it's not about the money."

WISCONSIN CONSTITUTION

SECTION 3. Every person may freely speak, write and publish his sentiments on all subjects, being responsible for the abuse of that right, and no laws shall be passed to restrain or abridge the liberty of speech or of the press. In all criminal prosecutions or indictments for libel, the truth may be given in evidence, and if it shall appear to the jury that the matter charged as libelous be true, and was published with good motives and for justifiable ends, the party shall be acquitted; and the jury shall have the right to determine the law and the fact.

WISCONSIN CODE

946.41. Resisting or obstructing officer.
(1) Whoever knowingly resists or obstructs an officer while such officer is doing any act in an official capacity and with lawful authority, is guilty of a Class A misdemeanor.

(2) In this section:

(a) "Obstructs" includes without limitation knowingly giving false information to the officer or knowingly placing physical evidence with intent to mislead the officer in the performance of his or her duty including the service of any summons or civil process.

(b) "Officer" means a peace officer or other public officer or public employee having the authority by virtue of the officer's or employee's office or employment to take another into custody.

(2m) Whoever violates sub. (1) under all of the following circumstances is guilty of a Class H felony:
(a) The violator gives false information or places physical evidence with intent to mislead an officer.
(b) At a criminal trial, the trier of fact considers the false information or physical evidence.
(c) The trial results in the conviction of an innocent person.
(3) Whoever by violating this section hinders, delays or prevents an officer from properly serving or executing any summons or civil process, is civilly liable to the person injured for any actual loss caused thereby and to the officer or the officer's superior for any damages adjudged against either of them by reason thereof.