Los Angeles ? It’s hard to know whom to sympathize with in this fight.

On one side: the paparazzi who stalk celebrities at doctors’ offices, with their newborns, when they are falling-down drunk.

On the other: a blogger who helps himself to those photos, scrawls comments on them and posts them on his Web site.

The owners of one photo agency here are so frustrated with what they consider to be blatant theft by self-styled “gossip gangstar” Perez Hilton that they’ve decided to make a federal case of it.

On Nov. 30, the agency, X17 Inc., known for the aggressive pursuit of celebrity prey, filed a $7.6 million federal copyright infringement lawsuit against Hilton, alleging that he has taken 51 photos without permission, payment or credit. The list of allegedly infringed photos is an almost poetic inventory of the state of pop culture and our obsession with it: “Pregnant Katie Holmes,” “Kevin Federline Pumping Gas,” “The New Slim Britney Spears,” “Britney Spears Exposes her Derriere,” “Britney Spears Exposes Herself (Again).”

Brandy Navarre, who co-owns the agency with her husband, Francois Navarre, said X17 is suing the owner of www.perezhilton.com not just because he doesn’t pay or credit them, but also because they don’t like his attitude.

While X17 has agreements with many gossip blogs – PinkIsTheNewBlog, PopSugar and SocialiteLife, among others – allowing them to post photos with proper credit and a link back to the X17 Web site, Navarre said she is tired of constantly reminding Hilton to credit X17 and has finally given up.

“We’ve had trouble with a lot of bloggers,” she said. “But he’s the biggest, and the most arrogant and pigheaded about it, frankly.”

Reached by phone, Hilton, whose real name is Mario Lavandeira, sounded miffed.

“She is suing me because I’m arrogant? That’s not what her press release said. My position is that I don’t think what I am doing is illegal and I am going to vigorously defend myself. I am willing to step up to the plate and fight for my rights and fight for the rights of all bloggers.”

Francois and Brandy Navarre, owners of Los Angeles photo agency X17 Inc., have filed a .6 million lawsuit against gossip

While it’s easy to be flippant about a battle between paparazzi and a sometimes juvenile blogger (who might draw cocaine or mucus trails from noses, mouth drool or other snarky/silly things on the photos he posts), there is a serious legal question at issue.

If it turns out that what he does is copyright infringement – rather than the fair use of newsworthy images, as Hilton’s attorney claims – it would not only put a serious crimp in the photo-driven field of gossip blogs but could also create new case law.

“The effect would be to eliminate the ability to comment on and transform photographs under the fair use exception to the Copyright Act,” said Hilton’s attorney, Bryan Freedman, of Century City.

It’s one thing to take somebody’s copyrighted work and turn around and sell that, he added, but to alter the work to achieve a satiric or humorous end is entirely different and is allowed under the law.

But X17’s attorney, John Tehranian, of Costa Mesa, doesn’t see it as fair use at all.

Hilton, he said, “is basically free-riding on the labor and efforts of X17 and its photographers who stay up all night and roam the city, and he simply right clicks and posts their photos.”

(Actually, Navarre said, she has altered her site so that Hilton can no longer right click to get photos, but he manages to get them anyway.)

This conflict is more than a juicy legal fight between two controversial enterprises. It’s also the manifestation of a cultural shift in how pop-culture-obsessed people get their fixes. These days, no one has to wait for People’s weekly appearance on the newsstand or even Access Hollywood’s nightly roundups.

Hilton, who said he earned less than $50,000 last year and expects to make into the six figures this year, is known for the dizzying pace at which he updates his site, sometimes posting two dozen or more times a day.

“Perez is not being targeted because he’s an affront to paparazzi everywhere,” said technology expert Matt Lum, whose company, Hoodlum Productions, provides technology expertise to both Hilton and X17.

“He is being targeted because the entire industry is undergoing a shift that was arguably brought on by blogs like PerezHilton.com, which took stargazers from a weekly or nightly television fix to an hour-by-hour, minute-by-minute, entertain-yourself-at-the-workplace enterprise.”

Hilton and X17 used to be allies, linking back and forth to each other’s sites. When Hilton grew tired of being admonished by Navarre to credit X17, he said, he retaliated by removing a link to her site. Hilton said the lawsuit is a public relations ploy aimed at squelching his blog to improve the prospects of hers, X17online.com, which was started in June and appears to be modeled in concept on what Hilton has done since he launched his current blog in early 2005.

Navarre scoffed at that.

“We are suing him,” she said, “because he is stealing our images and costing us money every day.”