A U.S. filmmaker who was barred from a state park for impersonating Bigfoot claims his rights have been violated.

Jonthan Doyle dressed up in disguise as the crypto-zoological legend of Bigfoot and then ran around Mount Monodnock Mountain in New Hampshire. After shedding his disguise he then interviewed onlookers about what they had just seen.

“People loved it. It was socially engaging,” he said.

However, when Doyle decided to return to the mountain last year, Monadnock Park manager Patrick Hummel was less than welcoming.

He ambushed Doyle during his next outing and informed him he had been banned from filming in the park until he obtained a permit.

Doyle then decided to take the issue to court, and his lawsuit is now backed by the American Civil Liberties Union.

The amateur filmmaker maintains that the state’s requirement that he obtain permit violates his right to free speech.

“The underlying activities are humorous, but the principle’s important,” an ACLU lawyer told the Associated Press.

“We’re talking about a very small-scale activity in a very large place. We don’t believe there’s any legitimate government role in regulation.”