Comment by swombat

Based on the fact that they decided to accelerate their internal encryption projects back in September, 2 months ago ( http://www.informationweek.com/security/government/nsa-fallo... ), I'm guessing they thought it might be possible, and in the wake of the Snowden revelations they decided it's very plausible (or someone showed them that slide ahead of time) and so they now effectively "know", though they're not keen to cooperate.