Another installment of an old controversy. I am a "flasher" (of headlights) myself -- but I don't do it as systematically as this guy did
"A judge in Florida ruled on Tuesday that flashing one's headlights to warn other drivers of speed traps set by police is protected by the First Amendment.
Ryan Kintner of Lake Mary, Fla. was pulled over and cited by a police officer in an unmarked car for doing just that. Kintner was at home when he saw a deputy park along a street and being using his radar gun. He got in his car, drove a little ways away and parked his vehicle so he could flash his lights at oncoming traffic to warn them. ...
Kintner, however, was not going down without a fight. He took his case to court, suing the Seminole County Sheriff's Office, with Attorney J. Marcus Jones arguing that ... 'Flashing your headlights is expressive conduct protected by the First Amendment.'"