Michigan - THE MICHIGAN PENAL CODE
CHAPTER LXXXII. TELEGRAPH AND TELEPHONE
MCLS § 750.539c (2006)
§ 750.539c. Eavesdropping upon private conversation.

Sec. 539c. Any person who is present or who is not present during a private conversation and who wilfully uses any device to eavesdrop upon the conversation without the consent of all parties thereto, or who knowingly aids, employs or procures another person to do the same in violation of this section, is guilty of a felony punishable by imprisonment in a state prison for not more than 2 years or by a fine of not more than $2,000.00, or both.