The social network built around short text messages was shut down from about 6 a.m. to about 8:30 a.m. Thursday by an apparently deliberate automated deluge of messages that overwhelmed its system., more 
and Web attack targeted Georgia blogger  The cyber attack that brought down Twitter for several hours Thursday was aimed at a single blogger located in the country of Georgia., more 

and Cassidy: What did people do before Twitter? Walk around stupid?  Life without Twitter is like a day, well, like a day without knowing what in the world is going on, IMHO., more