So get this. Your name’s Rodney Bradford, you’re 19, and at 11.49am on October 17 you’re typing at the computer at your parents’ place. Your parents live at 71 West 118th Street in Harlem, Manhattan. You live at the Farragut Houses, in Brooklyn. On October 18, you’re arrested as a suspect in a robbery that took place at Farragut Houses the previous day, just before noon. How are the authorities gonna believe you?

Well, turns out you weren’t just typing on your dad’s computer – you were on Facebook. And at 11.49am, you posted an update. You wrote something in street slang, something inane and personal about pancakes. But that’s not the point. The point is you wrote something, and it’s there on Facebook, with IP addresses and everything to prove your location.

The rest is simple. Your defence lawyer tells the Brooklyn assistant district attorney that the time of the robbery correlates with the time of the Facebook entry. The court needs evidence, so your lawyer subpoenas Facebook. The social networking company is a big believer in The Law and maybe sees an angle for a little media coverage (which it’s a big believer in as well), and thus quickly confirms that you made the entry from your dad’s house. The court scratches it’s head a bit, and then tells you you’re free to go.

Voila, legal precedent is set.

“This is the first case that I’m aware of in which a Facebook update has been used as alibi evidence,” a Dallas lawyer who studies social networking and the law told the New York Times. “We are going to see more of that because of how prevalent social networking has become.”

Read more: New York Times