Level3, the main owner of almost all the internet backbone in the USA is experiencing a world wide DDoS attack which has been going on since Oct 25th. It really ramped up yesterday and today. Certain ISPs, like AT&T use Level3's lines to route to access the data centers. Hell, from what i'm reading most of houston is down because of this attack right now. This is NOT SE's problem.

http://www.internethealthreport.com/...px?Period=RH24