The Interntubes are fragile

According to a Facebook executive, a fierce denial-of-service attack aimed at a single Georgian blogger yesterday was what brought down Twitter and disrupted service on Facebook, LiveJournal, Blogger and YouTube.

CNET News has the story:

The blogger, who uses the account name "Cyxymu," (the name of a town in the Republic of Georgia) had accounts on all of the different sites that were attacked at the same time, Max Kelly, chief security officer at Facebook, told CNET News. ...

Political conflicts between Russia and its former republic spilled online last year with DoS attacks and Web site defacements going in both directions.

Are these sites really this vulnerable? Do the Russians (clearly implicated here) have that much technical kung fu? Or is there more to the story than an attack on a Georgian blogger?

*Also, one year ago today Russian tanks rolled into Georgia, marking the start of a 5-day war.