A Vermont man who was arrested for flipping off a state trooper is suing both the officer and the Vermont State Police for violating his rights.

The lawsuit, which was filed Wednesday by the American Civil Liberties Union on behalf of motorist Gregory Bombard, revolves around a 2018 traffic stop in St. Albans, Vermont. According to court documents, Trooper Jay Riggen pulled Bombard over after seeing what he thought was Bombard giving him the finger as he drove by. Bombard says he hadn’t yet flipped off Riggen at that point, and was unjustly detained for questioning. Once Riggen cleared Bombard to go, Bombard flipped him off as he drove away, the suit says. Riggen pulled Bombard over for a second time, and arrested him for disorderly conduct, a misdemeanor. The charge was later dismissed.

“Vermonters who want to protest the actions of police through words or gestures have a constitutionally protected right to do so,” ACLU staff attorney Jay Diaz told the Associated Press in a statement. “This abuse of power by a Vermont state trooper is a clear example of just how over-policed our communities are.”