"They are just breaking the law," Cuban told a group of advertisers in New York. "The only reason it hasn't been sued yet is because there is nobody with big money to sue."
So, the logic there is that if a billionaire should invest a lot of money by purchasing it, they stand to lose a lot from the impending lawsuits. While he did criticize the level of piracy on YouTube and make that his primary concern, he didn't make any mention as to their underlying business model. It's quite possible that if YouTube reforms into a primarily legal video trading entity, things could change. That is, after all, their intention:
YouTube, which has nearly one-third of the U.S. Web video audience, three times that of Google Inc. (GOOG.O: Quote, Profile, Research), or twice that of News Corp's (NWSa.N: Quote, Profile, Research) MySpace, has been working on signing licensing deals with music companies and TV networks to ensure they are paid when users view their content.
His over the top critcism aside, he may have a good point. More than ever, companies are paying attention to pirated content, intentionally or otherwise.