http://www.google.com/support/youtube/bin/static.py?page...
Click on the contact us button on the right side and you get a form to complain about user harassment. That one seems to still work... for now.
Here is revision that worked for those who want to send a complaint -
Lectures on bomb making techniques. User is hosting 161 other videos on bomb making, IED’s, and how to care for/maintain assault rifles & machine guns. In addition, user is providing dangerous instructions on how to mix chemicals for explosives. This video should be immediately removed and this user suspended.
Thank you Celebrimbor! As usual, you come thru every time!