They provided a file hosting service, like Dropbox or Google Drive or Skydrive.
Judge Mooner, I'm pretty sure, doesn't own rights to Sinead O'Connor's music and yet DOJ is not currently suing YouTube because of http://www.youtube.com/watch?v=t77DexLMjOU
The rules for determining if a file sharing services like YouTube or DropBox or Megaupload violates copyright are not as clear as you seem to imply which is why e.g. Viacom lost it's case against YouTube (http://en.wikipedia.org/wiki/Viacom_International_Inc._v._Yo...)
It's far from clear that Megaupload violated U.S. law, let alone New Zealand's.