Cary's got
a sticky post over in the Fairfax County General forum explaining what happened.
Basically, someone tried to jack him for $100 and when he didn't cough up the dough (or the bitcoin, to be specific), they unleashed a botnet on FFXU that conducted a massive DDoS attack.
In simplest terms, there were all of a sudden hundreds, if not thousands of computers trying to get to FFXU, which caused all the problems.