BRIAN REILLY/ASSOCIATED PRESS

John E. Brennan stands naked after he stripped down while going through a security screening area at Portland International airport April 17.

A Portland man was exercising his right to free speech when he stripped naked at an airport checkpoint to protest TSA scanning procedures, a judge ruled.

John E. Brennan, 50, who went “Full Monty” at Portland International Airport in April, was acquitted of indecent exposure on Wednesday.

Multnomah County judge David Rees ruled that the First Amendment protected the 50-year-old frequent flier’s right drop his duds because he did it in protest, not to arouse or titillate the travelers around him.

Citing a 1985 state appeals court ruling stating that nudity laws don’t apply in cases of protest, Rees said, “It is the speech itself that the state is seeking to punish, and that it cannot do,” The Oregonian newspaper reported.

Brennan’s pals in the packed courtroom cheered the decision.

As they were leaving the court, one 70-year-old friend stuck a note to Brennan’s chest that said “Sir Godiva,” a reference to 11th century England’s Lady Godiva, who legend says rode a horse naked through the streets of Coventry to protest high taxes.

Brennan said he knew he wasn’t breaking the law when he dropped trou partly from his experience riding in Rose City’s annual Naked Bike Ride, during which Portland cops traditionally look the other way.

“I ride in it if it’s warm enough,” he told the Daily News.

The bearded tech consultant was dressed in work pants and slacks when he showed up at PDX for a flight to San Jose for business on April 17.

He testified that he refused to go through a full-body scanner at the security gate, and instead chose to receive a pat down and metal detector screening.

After the pat down, the TSA agents detected the presence of nitrates on his clothes.

Brennan got fed up and said he disrobed both in protest and to prove that he wasn’t carrying a bomb.

“I was mostly motivated by the absurdity of it all,” he told The Associated Press.

“The irony that they want to see me naked, but I don’t get to take off my clothes off. You have all these machines that pretend to do it.”

He was naked for about five minutes until police arrived, cuffed him.

In court, prosecutor Joel Petersen argued that Brennan couldn’t be protected by the First Amendment because he claimed got naked in protest after cops arrived.

Peterson said the conviction would serve a precedent, otherwise “any other person who is ever naked will be able to state after the fact” that they were protesting, The Oregonian reported.

Brennan said he wanted to send a message that the TSA was “broken” and wasteful.

“I’d been through metal detector and full pat down, but that’s the hassle we have to put up with,” he said. “The system is broken. I don’t know what the solution is to fix it, but I’m sure there are experts out there who do.”

The TSA said in a statement that it respected the judge’s decision to acquit Brennan.

“We continue to focus our attention on TSA’s primary mission of keeping our nation’s transportation system safe from security threats,” spokeswoman Lisa Farbstein said in an email.