Web 2.0 must-haves or “security headaches”? They’re the latter in an increasingly sensitive China — being blocked as they are in the PRC — and they could get blocked in America as well. The United States Military is thinking of a block that could envelope itself around Twitter and Facebook as well.

Boing Boing has it that the US military is no less harmonious, so to speak, than its Chinese civilian counterpart. It quotes Defense technology reporter Noah Shachtman as saying that that “the Pentagon may impose a very wide ban on Twitter and Facebook for security reasons”.

Obviously, censoring in the military is at least a bit more reasonable than stopping the citizenry from going to sites that could we — can we say this? — ”reactionary”. But once you start censoring — it’ll take quite an effort to wean away from the practise. Especially if it moves into civilian territory…