Copyright Conundrum: Was 'Public Domain' Music Silenced On YouTube?

Techdirt: "Mark Guertin writes in with an interesting situation that he's dealing with, which I think highlights some of the problems with copyright law today. Guertin put together a YouTube video of some swimming pugs as part of a promotion for a charity he's involved with. Knowing that music on videos is a potential copyright issue, he went to Wikipedia to find some public domain music, and chose Wagner's Ride of the Valkyries to accompany the swimming pugs."