The Associated Press Twitter account got hacked Tuesday, firing off a tweet claiming there was a bomb at the White House. The fake news went out to 1.9 million followers. No doubt further incidents will create havoc for Twitter -- not just for allowing someone to send inaccurate news that could endanger the security of a nation, but sending stock prices falling in the U.S. financial markets. Tony Romm tells us about prior incidents and how Twitter has yet to plug the holes.