Reply to Mixify Legal Agreement

I must confess I read that one during a coffee break but I still could not get a feel what it's all about.

For me it sounded like those who agree to this agreement have all the legal burden concerning ownership of the material. Does that mean that we need to have full copyright ownership to the tracks, or legally purchased them?

I don't mind the full copyright, i.e written and produced music by the owner, would force me to produce 50+ minutes of music each week. And I've done similar 'fake artist' mixes with all stuff coming from my studio with lots of pseudonym artists and remixes. However, I believe the intent of the contract is ownership of the audio, i.e not stealing music via bit torrent or something similar.

Anyway, I'm somewhat confused and don't want to sign this until I really understand the intent. Could anyone who read the Mixify contract chime in and explain it a little bit more, thx?