Maybe "thwarting" isn't the point. Why go to the effort of creating such a site in the first place? I doubt it's for the benefit of all mankind - it's probably to drive hits to a banner-laden website or some other for-profit scheme. I hardly think of people who create music distribution websites of any kind as some kind of benefactors for anyone other than themselves. If anyone is going to post tabs or lyrics or MP3 files or whatever of popular music it should be the artists and/or the publishers who created it because it's their property - and I don't see them doing that so noone else should either. Copy the "lyrics" from Time Magazine onto your website without permission (even with an "X" in front of each word) and the question of infringement isn't so vague.

We are musicians - the rules are in place to protect what we create, without which artists could not profit from their work and therefore there'd be no reason for the work to exist. I see other forums where musicians are constantly dissing copyrights like it was some evil empire thing (some of the posts here sound like that too). If anyone should be supporting copyrights, it's us, and our example is what others follow.