Sadly, it all comes down to lawyer's opinions. The opinion of Jon's lawyers about what he's allowed to have on his site, versus the opinion of The Biz's lawyers about what they can sue over. Obviously, if someone post's their own work, its OK. Problems happen with samples, tabs, and written music that was not composed by the member who posted it. And I'm pretty sure that Jon does not have time to make absolutely sure that doesn't happen. But you can be very sure that the publisher of some pirated music would find a lawyer that did have time to cause all manner of problems for this site. Its a bitch.