I don't speak lawyer too much but I would have to think breaking the TOS for a company can be prosecuted in some shape or fashion.
Copy/pasted this from a post on 2+2 in the thread they have about it there:
yeah especially considering ptr are based in london, as in english law actually respects intellectual property.
What went on was blatantly data mining of intellectual property, not to mention agreeing to pokerstars
ts and cs and then totally ignoring them. Stars have a ton of different things to use- they should pursue damages as well to hurt them :P Fwiw i signed up with ptr but what its done to heads up cash especially is a disgrace