I don't know about all cases, but in some cases, that's spot on. The Government doesn't need to know WHAT you discussed with Saddam Hussein, they just need to know that you were there at some time talking to Saddam to place you under the radar. In other words, 'information about information'.
And that's exactly how they're picking some of their drone targets, too. If you've talked to the leader of al qaeda, it doesn't really matter what you discussed (maybe he was just quering about the neighborhood or whatever), you'll probably end up dead.
So yes, metadata is very much "content", and can be very, very dangerous in the wrong hands.
That is the most ominous scenario, which is likely complete fiction (so far).
Finding the high value targets requires good detective work. Blowing up acquaintances is destroying good leads. The metadata creates leads, and helps narrow them down to a more promising and manageable subset.
