body: I apologise in advance if this is a silly question.
  
  
  Let's say you have a person A who bought a song from an online service, and is distributing it without permission. Person F obtains a copy of this song and distributes it himself.
  
  
  I can understand why person A might be at risk of a lawsuit, as he's broken the contract agreed upon when purchasing the song. But Person F hasn't agreed to anything, hasn't signed any contracts and hasn't gone through a shrinkwrap agreement.
  
  
  So why would Person F be at a risk of being sued?
  
  
  
title: Why is it possible to sue non-original distributers of Pirated items?