Amid honking from cars below, Daniel Martins was doing what he often did on Fridays, advocating for the impeachment of President Barack Obama from a pedestrian bridge over the Long Island Expressway.

On the sunny day last June, however, the Hofstra University student was confronted and arrested for disorderly conduct and criminal nuisance by Nassau County police who claimed his signs and flags might cause a car crash.

The criminal case was dismissed on free speech grounds in December and Martins now is seeking $2 million in a federal lawsuit, alleging the arrest was illegal and intended to stop his exercise of First Amendment-protected rights.

"It wasn't a problem for anybody but the police," says attorney Thomas Liotti, a two-time Obama voter representing Martins. "It wasn't distracting. I don't think anyone took much note of it because these things happen all the time in New York."