Mike Skiff, a self-described gay journalist, sued Baron Cohen and others involved in the 2009 film "Bruno" for more than $25,000 in damages for alleged physical and emotional pain and suffering.
His lawsuit claims he was shoved, pulled and threatened with wooden signs as he filmed the comedian in character as gay Austrian fashion journalist Bruno.
The lawsuit said Skiff recognized Baron Cohen during the pro-gay marriage rally in downtown Los Angeles in Nov 2, 2008, and began filming him.
Footage posted on YouTube by Skiff's company, Third Rail Media, showed the actor-comedian standing among anti-gay marriage protesters who had also assembled in the streets.
A man is heard shouting, "I know that's Bruno - I can get as much as I want," before being harangued by the crew. One portion of the video shows Skiff pulled away from Baron Cohen before police intervene.
An e-mail sent to Baron Cohen's publicist, Matt Labov, was not immediately returned.
Skiff also claimed the actions of the "Bruno" crew violated his civil rights and that their appearance at the rally was intended solely to create conflict for the film.
Baron Cohen's in-your-face comedy has provoked several lawsuits since his 2006 film, "Borat: Cultural Learnings of America for Make Benefit Glorious Nation of Kazakhstan," became a smash hit, but courts have sided with the comedian.
"Bruno" also has sparked its share of legal wrangling.
In June 2009, Richelle Olson sued, claiming she suffered brain injuries when Baron Cohen caused her to fall after a confrontation at a charity bingo tournament in Lancaster, Calif. The case is on hold while the woman's attorney appeals a court ruling.
In December, a Palestinian shopkeeper portrayed as a terrorist in "Bruno" sued Baron Cohen and others for libel and slander.
The Bethlehem shopkeeper and father is identified in the film as a member of the militant Al-Aqsa Martyrs' Brigade. He is seeking $110 million, and the case remains pending in a Washington, D.C. court.