Originally Posted by Kingfish

There is a difference between trademark and copyright law that is what some of you are missing. There is no safe harbor for using someone else?s trademark. Say you have exclusive content and you put a watermark of your registered trademark on all the videos. Now say someone uploads that to a tube ? the tube site owner is liable for the infringement of your mark. He can?t use safe harbor as a defense. For now the smart thing to do would be to register your marks and mark everything with your registered mark.
http://www.uspto.gov/go/tac/doc/basic/howtofile.htm