"Careful, that's a Louis Vuitton," says Zach Galifianakis' character in the Hangover II. Well, it turns out that (gasp) his Louis was a fake!

On Thursday, luxury fashion brand Louis Vuitton S.A. filed a suit in federal court against Warner Brothers Entertainment for "trademark infringement, false designation of origin and unfair competition" under the Lanham Act.

The offending 100 year old Toile Monogram bag was not a product of Louis Vuitton, but rather, a knockoff distributed by Chinese American company Diophy- which is currently entangled in another lawsuit with Louis Vuitton for selling counterfeit goods in the United States.

The suit claims that the film, "prominently features an infringing travel bag." LV also claims that it has asked Warner Brothers to adjust the scene before the film's DVD release, but that the studio has refused to do so.

For a company that prides itself upon fighting piracy, Warner Brothers should know this: Fakes fuel feuds. Especially in fashion.

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