If they are pirating vBulletin you can always report them here:
http://www.vbulletin.com/piracy.php
For modifications/styles you'll have to let the author of said modification know, Jelsoft can't go around protecting work they do not hold the copyright to in the first place.
Also keep in mind that it takes awhile to have such sites taken down. Jelsoft is not the almighty hand of god that can make things go away just like that.