I was reading the Overture boilerplate that advertisers agree to, and found this gem: "You hereby grant Overture the irrevocable right to access, index, cache, and display (in connection with your listings) the Web site(s) to which your listings link, or any portion thereof, including by any automated means including web spiders or crawlers. This grant specifically includes Overture's right to create and display copies of any and all text, graphics, images, audio, video, and all other material included or found on such Web sites or portions thereof, including the right to create and display thumbnail and full-scale copies of any images or video included on or found on such Web sites or portions thereof."
In short, it seems that if you have ever advertised at Overture they have an irrevocable right to all of your content. Maybe that's why Yahoo purchased them - not for PPC revenue, but because OT now owns most of the content on the web... ;) I suppose a tight reading of "in connection with your listings" might limit what they could do with it...
