Digg.com, whose executives couldn't be reached for comment, isn't the first site to face legal problems from user-generated content.

FORBES: Digg's DRM Revolt

On May 1, someone posted the code, which allows software developers to copy content from high-definition discs, to the social news portal Digg.com.

FORBES: Magazine Article

Digg.com is a social content site - one which combines social book marking with blogging - and all democratically controlled by its users.

BBC: Picnik website

In the case of the social news portal Digg.com, a meltdown.

FORBES: Magazine Article

"Social media" sites like Digg, Reddit.com and Newsvine.com let users submit and rank news headlines and other links to sites around the Web.

FORBES: Magazine Article

For example, you could vote up, or "digg, " a story on Forbes.com without ever having to leave the site.

FORBES: Social Media

Dozens of sites participated, including Aol, The Huffington Post and Digg, and more than 100, 000 people and sites have pledged to participate on the Causes.com page for the Web Goes Silent campaign.

CNN: Websites go dark for Sandy Hook moment of silence