Most comics don't have the restraint to keep a good joke to themselves. Yet when their own joke comes out of another's mouth, every comic cries foul. Unlike other professionals of the word -- screenwriters, poets, novelists -- comics rarely have the luxury of copyright laws to protect their work. By the same token, plagiarism is nearly impossible for a comic to prevent. The nature of the profession, which thrives on  mostly unrecorded stand-up performances at comedy clubs, leaves no documentation to protect against fellow comics in the audience stealing the jokes that get the most laughs.

Traditionally, stealing jokes and the ensuing battles over authorship is a behind-the-scenes affair. The comic and actor Joe Rogan, however, brought comedy's cardinal sin to a public audience when he confronted Comedy Central's primetime star Carlos Mencia on stage at the Comedy Store in Los Angeles this past February. The ugly spat found its way to YouTube, where close to a million people have watched the video in the past six months. But to a greater effect, feud has brought attention to an issue that was once only the worry of comedians.

The many claims against Mencia's alleged comic thievery were an occasion for Gelf Magazine's Adam Conner-Simons to explore the unwritten ethics of stand-up comedy. He finds that for purists like comedian Steve Hofstetter, 'The root of comedy is truth, and if you're doing someone else's truth, you're not doing comedy.'

What constitutes telling the truth, however, and stealing a joke is a murky matter for some. Comedy Central's Skyler Stone tells the magazine, 'There's so much parallel thinking because we [comics] are all trying to tap into the same public consciousness.' So jokes about current issues -- like the absurdity of building a wall along the US-Mexican border -- end up sounding like an echo chamber on comedy circuits.

Of the countless comics making the rounds on the scene, only the handful with television exposure and CD releases are able to stamp a joke as their own and have any legal force behind it. These are the same comedians, however, that can use a copyright to lay claim to hijacked material. Radar's Larry Getlen explains the situation like this: 'When a comedian is the first to tell a stolen joke at a major gig or on national television, the public associates the material with that comic... A comedian can write the best joke of his career only to lose it to a sort of 'finders keepers' rule.'