Since I'll often figure out how a song is played by watching a video of a performer, or by listening to it, I wonder if that should be banned, too, because if I listen to the album or watch a performance and figure it out, that's like having a tab for the song in my head! And god forbid, but I might play it in front of someone else who may also figure it out.

I don't see the difference between this phenomenon and online guitar tabs (although I think tabs can promote laziness, not to mention well over three quarters of them are absolutely wrong).