When UC Berkeley journalism graduate student James Karl Buck was grabbed by police in the Egyptian industrial city of Mahalla El-Kobra while photographing a noisy demonstration, he sent a one-word text message to Twitter: "Arrested." That eventually got him out of jail. His Twitter followers -- friends who receive a Twitter user's messages are known as "followers" -- promptly called UC Berkeley, the U.S. Embassy in Egypt and the media. The University then swung into action and got him out.