I am the very first in line to say people have to raise their children how they see fit (barring abuse of course) Teach the values and morals you want taught, teach the level of respect for themselves, and others you feel is right, etc. You brought them into the world, you are responsible for their actions until they reach a majority, nobody will care for and love them like you do.
If there is a toy, band, video game, movie, clothing......WHATEVER you feel is counter productive to the goal you are trying to achieve in raising your child, I have no issue saying BAN IT.
Though (as mentioned I think), in most forbidding/banning cases, it makes something seem so much more interesting than it would have, LOL