Michael Elli warned other drivers of a speed trap while driving in Ellisville, Missouri and received a ticket for doing so in March 2012.
Now, he has filed a lawsuit that claims his First Amendment rights were violated during last year's incident.
Elli saw a police officer parked alongside the road with a radar gun and so the motorist flashed his lights to warn oncoming drivers from the other direction.
"It's like when you are on a vacation, and you stop at a truck stop and mention to a person there that you saw a speed trap a mile down the road," Elli's attorney Grant Doty told ABC News.
"Just as the government cannot criminalize you in the situation in the truck stop for sharing a message verbally, the government cannot criminalize Mr. Elli for sharing a message with his headlights."
"We think that the policy and practice is unconstitutional and we are interested in challenging similar laws all throughout Missouri as well," stated Doty.
The police officer gave Elli a ticket for violating a local law against flashing lights on certain kinds of vehicles.
However, Elli's lawsuit claims: "No reasonable officer" would have written the ticket and the police officer did so "in retaliation for having engaged in expressive conduct protected by the First Amendment."
"It is a widespread practice of the City of Ellisville to pull over, detain, and cite individuals who are perceived as having communicated to oncoming traffic that a speed trap is ahead by flashing their headlamps, and then prosecute and impose fines upon those individuals," claims the lawsuit.
Elli is suing the city of Ellisville in a class-action lawsuit on behalf of all Ellisville drivers.
The city recently told the court that it instructed its police officers not to issue tickets to "motorists who flash their headlamps on and off … in both emergency and non-emergency situations."
Source: ABC News