It's possible that it could be used by terrorists to transfer value around. But honestly at this point I highly doubt it, and I would expect most groups to have some sort of network between countries where they can exchange money. I know there is a massive non-terror related network for transferring money throughout the muslim world already.
You're thinking of something called a hawala network, and those are (probably) way more closely monitored by US intel than BTC currently is. I definitely understand why people are upset the US military is monitoring BTC, but at least it's really nothing more than par for the course. It doesn't seem like they have anything against BTC
in particular, just kind of the idea of something unmonitored that can be used to launder money. And, by the way, preventing money laundering is one of the easiest and most effective ways of reducing terrorism. Just saying.