I downloaded Rammstein's Amerika but it was like just one specific verse and chorus repeated. It was really weird. It took my a while to notice because I didn't know German. My best guess is someone took a free sample of the song from somewhere and edited it so it was longer by repeating it a couple times.
Also, a few of the Nightwish songs I downloaded had an announcer in the middle of the bridge say something like "You are listening to Nightwish's new song Blah on the album Once." Maybe it said something about being able to buy it on iTunes. That one was interesting because it definitely seemed legit. I guess some artists released stuff like that knowing people would steal regardless so they wanted a version with instructions to buy it if you liked it. To this day when I'm listening to those songs I hear the voice in my head when the song gets to those parts.
If it was a popular torrent with a lot of seeders, it was probably still working but you never got selected. Could also happen when it was the opposite. If there was like three seeders and no peers, when you finish you're just sitting there with the other folks with no one to seed to.