Live Nation has now joined AEG in filing a lawsuit, this time against several John Does in advance of this weekend's OzzFest, featuring Ozzy Osbourne, in Devore, Calif. Here's the complaint, filed in U.S. District Court in California on Tuesday.

Earlier this week, AEG attempted to get a court order that would have federal and local law enforcement authorities seize and impound trademark-infringing gear at this weekend's Mile High Music Festival.

The move to pre-sue anonymous troublemakers who haven't yet committed misdeeds follows similar efforts by UMG over a Lady Gaga concert earlier this summer.