Try Limewire and Sharebear, my daughter has decimated computers in her possession using that crap.
Really what it comes down to, is know what you're downloading, she could never be bothered to scrutinize anything and happily downloaded trojan horses and open them right up without even looking.
And it was my daughter that downloaded the latest Rap song the day it came out, that resulted in me getting an e-mail from our ISP saying the owners of the song had indentified our IP as illegally downloading it. I had to chew her and the rest of the kids out.
Best I can tell though, it was just a warning that the ISP passes along when they get them. It mentioned their policies, and violating can result in bans. But it did NOT say it was our only or last warning.
Comcast has a record of giving people one warning then banning them for life, NOT particularly enthusiased about losing our only access to high speed internet, even though I can't stand COMCAST and would switch in a second if I had an alternative.
I've seen posts where people have said they got several of these warnings, and it never resulted in anything. NOT that I'm recommended tempting your ISP or song owners by ignoring them.
From what I read, keeping file sharing running constantly, with material up being shared after you've downlaoded it, increases your exposure and chances of being noticed, makes sense, but NOT breaking the law is the best way NOT to get in trouble.
Someone said there are proxy servers that you can use to hide you IP address, I don't know how to do it, and certainly won't let my kids do it, I've just uninstalled any file sharing and told them don't do it anymore, if they get caught another time we may lose internet.
Funny thing is, most of the people getting sued for downloading the hurt locker, its adding injury to insult, god that movie was horrible BS totally created from bogus steorotypes that are totally untrue.