The news of a gunman at the Discovery Channel's headquarter's Wednesday was broken by Twitter, not traditional media.

“As it has with other breaking news events — the landing of a jet on the Hudson River in 2009, the 2008 massacre in Mumbai — the story unfolded first in hiccupping fits and starts on Twitter, the much-hyped micro-blogging service that has turned millions of people into worldwide gossips, opinion-mongers and amateur news reporters,” The Washington Post's Howard Kurtz reports.
Before camera crews and reporters could race to the scene, a shot of alleged hostage-taker James Lee was flashing around the world via Twitpic. The shot — full of menace and dread — was apparently taken by an office worker peering from a window several floors above the Discovery courtyard. The photo was apparently passed from an unidentified Discovery employee to another, who posted the photo on and then distributed it via Twitter.