The Motion Picture Association of America (MPAA) doesn't feel that they should be required to provide proof before they sue people for copyright infringement and piracy, at $150,000 a pop. This all stems from a precedent case in which a man was sued for sharing music online, and was found guilty because he had an open share folder on Kazaa, and not because there was any proof that songs were actually shared. This suit was worth $220,000.
Since the ruling, however, the judge who made it has decided that he would not have set the same precedent if asked the same way again. Still, this opens the door for the MPAA to say that intellectual property theft is too hard to prove, and that they should be able so sue on less proof, so there you go.
The Consumerist: The MPAA Says They Shouldn't Need Proof To Sue You