Does Anyone Say Anything Useful on Twitter?

Gawker reported yesterday, and the folks behind Twitter vehemently denied, that Twitter was giving backdoor access to a federal intelligence agency who wanted to monitor tweets and their origins. Lots of federal agencies have Twitter feeds, so I imagine the service is reasonable about working with agencies, dealing with user agreements, etc. But I have a hard time imagining that a lot of actionable intelligence is going to get gathered from a service that's specifically about broadcasting. It makes a lot of sense that an organization like the State Department would want to take a look at trends out of a place like Iran as a sample of what the population is up to. But it's hard to believe that anyone's going to advertise a covert plot that would require them being tracked down on a service that seems increasingly like a practice ground for stand-up comedy punchlines.