I imagine the perpetrators of extremist based terrorism see this erosion of civil liberties as an enormous win.
Yes. Snowden is definitely a hero, of dare I say it, historic proportions.
Bin Laden wasn't the first person to predict that an increase in terrorism would lead to an increase in "Orwellian" practices.
It might be worth an ironic smirk to real terrorists, but Al Quaeda etc. are surely not out to reduce our civil liberties but to establish governments to their own liking, primarily in certain definite regions. The revelations may teach them something about the reach of US intelligence, but they'd have been foolish not to assume something like this was going on.
You are almost certainly wrong. Most terrorists have political goals that have nothing to do with US civil liberties and more to do with foreign policy.