[adrusi]

Except now everyone knows a lot about the capabilities of the NSA, and every serious criminal is already using the strongest encryption available and doesn't have any course of action for when the NSA is onto them.

It would be like if the British "blew their cover" and the Germans could only respond by completely ceasing all encrypted communication. Not the best possible outcome if they do, but still a positive outcome.

It's an even better outcome for cybercrime, since ceasing all communications would mean ceasing everything. If the NSA did this, the criminal would probably just stop operating, which means they might not be brought to justice, but at least the attacks would stop.