I'd be more inclined to call it a surprise attack if they used something as stupid as twitter. Why should the attackers expect anyone to take such an informal announcement like that seriously? But like I said, because I'm so far out of the loop I don't understand why things like twitter and facebook have to be serious business. Back in the day people talked to each other face to face instead of through a camera on top of a computer screen.
By the way, I never said I was actually going to "kill" anyone...