Every single song is linked to the account of the customer and the Feiyr SoundCloud account. Only these two accounts can upload a track or versions of it at SoundCloud.
SoundCloud continuously checks whether tracks have been uploaded without permission. If so, theses tracks will immediately be blocked and the Feiyr user will be informed. If a track still appears illegally on SoundCloud, the artist can let him lock directly from Feiyr.