1. Hacked A.P. Twitter Kun-Mao Chao Kun-Mao Chao ( 趙坤茂 ) Department of Computer Science and Information Engineering National Taiwan University, Taiwan A note given in BCC class on April 24, 2013

2. A False Alarm 2 Source: AP; The New York Times 4/23/2013

3. A Hacked Account The Twitter account of The Associated Press was hacked on Tuesday and erroneously sent out a message saying there had been explosions at the White House, injuring President Obama. Within a few minutes, Twitter suspended the account, and Julie Pace, the chief White House correspondent for The A.P., announced at a White House briefing that the account had been hacked. 3

4. Clarification Jay Carney, Mr. Obama’s press secretary, confirmed that the president was unharmed. Editors at The A.P. soon followed with a statement saying that “The @AP twitter account has been hacked. The tweet about an attack at the White House is false. We will advise more as soon as possible.” 4

5. The Dow Jones Industrial Average plummeted! The Dow Jones Industrial Average plummeted more than 150 points when the news broke on Twitter — an indicator of traders’ presence on the social media platform — before immediately recouping the losses after it became clear that there had been no attack at the White House. 5

6. The Dow Jones Industrial Average plummeted! 6