http://tickets2.burningman.com/info.php?i=2386

"Use of Images"
I UNDERSTAND AND ACCEPT THAT NO USE OF IMAGES, FILM, OR VIDEO OBTAINED AT THE EVENT MAY BE MADE WITHOUT PRIOR WRITTEN PERMISSION FROM BURNING MAN, OTHER THAN PERSONAL USE. I understand that I have no rights to make any non-personal use of any image, film, or video footage obtained at the event, and that I cannot sell, transfer, or give the footage or completed film or video to any other party, except for personal use, and I agree to inform anyone to whom I give any footage, film, or video that it can only be used for personal use.

I agree that, in the event I post, or allow to be posted, any images (still or video) on a personal website or a website controlled by a third party, that (1) in the event Burning Man notifies me that any such images must be removed, for any reason whatsoever in Burning Man's sole discretion, I will promptly remove or cause to be removed those images; and (2) I will place, or cause to be placed, on any website in which such images are displayed a notice that the images can be used only for the poster's personal use and not for any other purpose and that downloading or copying of the images is prohibited.

I further agree that, in the event any third party displays or disseminates any of my images in a manner not authorized by this agreement, I assign to Burning Man the copyright so that Burning Man can enforce against the third party any restrictions concerning use of the images, and I appoint Burning Man as my attorney-in-fact to execute any documents necessary to effectuate such assignment.