Teenage girl arrested for tweeting al-Qaeda 'threat' to American Airlines

The 14-year-old girl wrote: "hello, my name's Ibrahim and I'm from Afghanistan. I'm part of Al Qaida and on June 1st I'm gonna do something really big bye".
American Airlines responded to the message, saying: "Sarah, we take these threats very seriously. Your IP address and details will be forwarded to security and the FBI".