I'm in the middle of a lawsuit now.
I received a letter from a scummy law firm in another city. They blitzed the city I live in... more than 10,000 letter sent out apparently. They had "proof" in the form of an IP address that was apparently assigned to my account at my ISP and a P2P log showing that someone at that IP apparently downloaded a movie made by the production company they were representing. I've never heard of the movie. I go look it up on IMDB... it appears to be some terrible low quality, low budget SciFi that no one watched... ever. I certainly had never heard of it, and I never downloaded it.
The law firm was demanding money. If I didn't pay up the "I'm guilty" fee, then they said I'd be taken to court and sued for 10's of thousands. I called a lawyer who is well known for defending this sort of crap. He looked at the letter I received, immediately recognized it, and said.. IU know these guys, let me add you to the big pile of people I'm representing on this same threat and I'll make it go away. That was over 2 years ago...
I have had two letters from him informing me what's going on. Basically he said that this rogue law firm was full of crap, that there was now a Class Action suit open against them and they had a fixed period to reply... the law firm never said a word, so now the second letter said that it's going to court with more than 1000 people being represented... but it could take years for it to reach an end. Basically he said.. don't worry about it, it'll be tied up in the courts for years and it's not cost me a cent.