LA photo agency X17 Inc., claiming “Hilton used 51 [of their] photographs without permission, payment or credit, including images of a pregnant Katie Holmes, Kevin Federline pumping gas and Britney Spears showing her, um, assets,” has filed a federal copyright infringement lawsuit against Perez Hilton.

“We’ve had trouble with a lot of bloggers,” X17 co-owner Brandy Navarre told the Los Angeles Times for a story on its Web site. “But he’s the biggest, and the most arrogant and pigheaded about it, frankly.

“He is stealing our images and costing us money every day,” she said.

Hilton, whose real name is Mario Lavandeira, said he believes he has done nothing illegal.

“I am going to vigorously defend myself,” he said. “I am willing to step up to the plate and fight for my rights and fight for the rights of all bloggers.”

His attorney, Bryan Freedman, said Hilton has a legal right to make satirical or humorous use of newsworthy photographs.

If the copyright lawsuit succeeds, “the effect would be to eliminate the ability to comment on and transform photographs under the fair-use exception to the Copyright Act,” Freedman said.

But X17’s lawyer, John Tehranian, argued that Hilton “is basically free-riding on the labor and efforts of X17 and its photographers who stay up all night and roam the city.”

Seven other photo agencies sent Hilton a joint letter demanding that he stop using their photographs but they have not sued, the Times said.

ModFab seems pretty ambivalent about the whole thing:

[I]t couldn’t happen to a more deserving guy. I detest the cult of blog celebrity, as most regular readers know. (Have you seen that terrible Advocate story on Perez and Andy Towle? The photographs are hilarious…they look like Devo without the red cone hats.) But at least Andy can put a subject and a predicate together. Perez is also a terrible writer, a clingy hanger-on. His success is only due to chasing the absolute lowest standard of blogging.

You can find Maria on MySpace here and read her current call for essays on femme identity here. Pick up Queer Shorts, her new anthology, at MergePress.com.