Doing some research I ran across this court case
Talks about how the police ticketed a person for flashing their high beams during the day. They were obviously warning on coming drives of a speed trap. The ticket got thrown out after taking it to the State Supreme Court. They said the law was missapplied.
But there was a desenting opinion, here it is and one of the Judges was not there so this case could have gone the other way.
This is interesting, the judge felt the person should have been cited for obstructing governmental operations.