The American Civil Liberties Union has sued Grand Rapids authorities, saying police in the western Michigan city routinely make unconstitutional arrests for trespassing on the property of businesses open to the public.
The group said Wednesday it filed the federal suit on behalf of two men who were arrested but later cleared of trespassing charges.
The ACLU says police long have asked businesses to sign "letters of intent to prosecute trespassers" and says police use them to arrest people without checking first with business operators if they're unwanted.
Grand Rapids City Attorney Catherine Mish says she's aware of the suit but won't comment before officials review it.
The ACLU says one plaintiff spent three days in jail after stopping his car at a gas station.