Just to play devil's advocate here, what about spying on known criminals and suspected terrorists?
Aw, that's easy, newheart: probable cause. If there's legitimate probable cause to believe crimes have been or are being committed, spying may very well make sense; there's no justification, however, for blanket spying on any one person without probable cause, spying en masse without it, or regarding Tea partiers, Christians, abortion opponents, et alia as dangers to the nation.
The feral government has declared its indpendence of both us, the people and the Constitution.
It is indeed easy, but sometimes in these discussions we jump over the obvious when it may not be obvious to all.