Some major websites went dark briefly Friday in a "moment of silence" for the victims of last week's shooting at Sandy Hook Elementary School in Newtown, Conn.
AOL, Yahoo, The Huffington Post, Digg, and more than 100,000 people and sites have pledged to participate in Causes (dot) com's Web Goes Silent campaign.
People and companies across the Internet were also spreading the word by tweeting their intention to go quiet Friday with the hashtag #momentforSandyHook.
Silicon Valley venture capitalist Ron Conway promoted the online moment of silence, which is part of a larger campaign for federal gun control legislation.
Conway is leading the Causes campaign along with other big names including Ryan Seacrest, Jack Dorsey, Britney Spears, MC Hammer and Suze Orman.
Sites that participated in Friday's moment of silence were invited to do so on their own, or to embed an official badge with a green ribbon on their sites.
Sites using the code appeared grayed out, save for a white box reading "We are observing a National Moment of Silence for the victims of the Sandy Hook tragedy."
Conway joined other tech notables and celebrities to demand action for stronger gun control in a full-page ad in the Wednesday New York Times.
The ad was run by Mayors Against Illegal Guns, a lobbying group of more than 700 U.S. mayors which began after the Aurora, Colorado, shootings in July.
It was seen a surge in new support after Sandy Hook, although at the NRA press conference today, the group called for more armed security at schools.
Time for more gun control regulations?