An interesting question to which I don't have a firm answer. I am drawn to the "fire in a crowded theater" argument, although it isn't a perfect analogy.
Perhaps a thought experiment might help. If you discovered a non-classified way to disable all American military weapons (perhaps some new technology that you personally invented) would it be lawful to post it on the internet? Would it be moral and ethical? Would it be the right thing to do?
I think that correctness of behavior is determined by its forseeable consequenses. The law is a shabby subset of morality.
Soon it will be possible for anyone with a PDA/camera or cell-phone/camera combination to monitor people around them using face and speaker ID software. This will make it impossible for people like Whitey Bulger or Lon Horiouchi, to pick two provocative examples, to walk around without being detected.
Is it a crime to shout "Lon Horiouchi!" in a crowded gun show.
My opinon is that the more that people can snoop, the more they will snoop on government officials. No more anonymity. Some IR cameras could have unmasked the Elian raiders. I think this is a good thing.