Theft is theft. If you didn't pay for it you are a thief. Anyway, just like porn - there will always be illegal music. Many countries are not subject to these laws. Just have your webspace in some exempt country and you can't really be arrested. You could post the songs right on your site.
Also, hasn't anyone ever heard of newsgroups? They are so much better than napster or kazaa, etc. Use program like sb news newsbot from
http://sb-software.com/ and you will fill up your harddrive with mp3's posthaste. same with porn.
Misc. sites like this one tfproject.org will continue to somehow make material available - sort of like they already do with jpgs of porn - no different.