My question is why does CENTCOM even need a presence on Twitter?

U.S. Central Command twitter hacked (http://www.cnbc.com/id/102330338)

So they can monitor the monitors of the monitors ;-)

I have wondered the same thing. Years and years ago we were taught that "loose lips sink ships" and that "the bear was watching us." I wonder how much "possible intelligence value" or PIV is gleaned from those sources. Not big stuff, mind you, just lots of little pieces that you can put together to figure out what is going on. Always observe OPSEC!