This whole prism thing isn't about stopping terrorist attacks though that's the excuse they peddle it out under. It's simply about power and control and chipping away at our rights bit by bit until we have none left. They need to be held accountable for this bullshit.
That is one aspect. But imagine what happens
if and when there is a terrorist attack.
The Government must at least be seen as trying hard to stop the attacks.
PRISM provides the government with an excuse - "We tried our best, but a few managed to slip through our checks".