Welcome to Grouper: P2P with a twist. When you “share” a music file, it just streams from one machine to the other, so you never really…release the track. No one “gets” the track, so is there a copyright problem?
I imagine this is akin to me sticking big speakers in the windows of my house, facing them towards the street, and playing a song for everyone on the block. Sure, they’d want to kill me, but have I broke any copyright laws? I never “gave” them anything.