LOS ANGELES - It's no laughing matter. Conan O'Brien is accused of stealing jokes.

A federal judge is letting an unusual lawsuit proceed on a trio of jokes O'Brien claims were originals.

A San Diego writer accuses the late-show host of plagiarizing punchlines on Caitlyn Jenner, Tom Brady and the Washington Monument.

Robert Alexander Kaseberg says he posted jokes online in 2014 and 2015 that O'Brien later repeated almost verbatim on his "Conan" show on TBS.

University of Virginia law professor Dotan Oliar says comics are often accused of stealing material, but it rarely leads to court. Most disputes are settled amicably backstage.

The judge says Kaseberg's one-liners are entitled to "thin copyright protection."

A judge or jury could decide if a theft occurred if it goes to trial.