After a series of complaints from foreign entities and groups Twitter finally became the target of a distributed denial of service attack (DDoS). Somehow that was just a question of time before that happened: If you can't get the people to shut up than you go after the medium they use to communicate. Twitter is currently operating normal but the DDoS seems to be ongoing according to Twitter's official blog.
Update: Rumors say that a massive wave of spam using Twitter brought it the service to it's knees, not a planned DDoS attack.
Update2: It is now confirmed that it was a DDoS attack on a particular account - see post from 08/11/09
Link to Twitter's official blog: http://status.twitter.com/post/157191978/ongoing-denial-of-service-attack
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