For example, If Freezepop wanted to put Sprode on the Rock Band Network (yes, I know it's already in the game), then would it get denied because they mention Target? Or another example is Conventional Lover. There's all kinds of copyrighted stuff in that song, would it get turned down?
I know public domain songs are out, but what if, in a song about something else, you mention someone named Mary having a little lamb? Or could you have a song about copyrighted material if you don't mention it explicitly?