Looks like snapchat was hacked on new years eve and the hackers released a big database with 4.6 million user's phone numbers. Here is an article on it : http://gigaom.com/2013/12/31/snapchat-hacked-4-6-million-usernames-and-phone-numbers-lifted/ You can check if your account's information got leaked on http://findmysnap.com/ It sucks that this happened right on the eve. I hope they don't release passwords or other information.