I've been interviewed by the FBI twice for being involved in international software piracy in two separate cases. This was before Bittorrent existed. In each case over a dozen people went to prison. They let me slide the first time because I wasn't high up in the chain but they called me on the second case after the interview saying they were considering charges against me. They had a thick file that I got to see of my digital activities.
I didn't learn my lesson the first time and propelled myself up the scene after a short hiatus. I feel my saving grace was that I perma-retired months before the second big bust. I wrecked my life for these groups so I was trying to go legit. I didn't get charged nor did I turn into a snitch.