So I think this came from an interview with Dolph Lundgren:
Steven Segal was at some Hollywood party giving it the absolute biggun’ about being the hardest man in Hollywood (apparently he was a producer’s PT that was given a role in films for a bet). JCVD (who’s a real black belt) arrived at the party and Segal tried giving him a load of attitude to impress people. JCVD squared up to him and Segal got scared and left.
According to this story, JCVD ended up on a bar crawl around LA chasing Segal around a load of bars. Segal ended up having several shades of shit kicked out of him in the VIP suite of a strip club.