I've got a few friends who are affected by this who haven't tweeted in months. All posts come from the web interface. Can't find any news or security sites with more info.
Seems to be picking up steam..<p>Real-time search:<p><a href="https://twitter.com/#!/search/realtime/cnbc10home" rel="nofollow">https://twitter.com/#!/search/realtime/cnbc10home</a>