Let's say you're in a position to stop 9/11 by agressively spying on Al Qaeda prior to the attack.
Let's say you're aware that Al Qaeda has sleeper cells planted in the US. They send these people in here to live amongst us, to blend in, and then at some future point, to come together, board a series of passenger jets, highjack those flights, and use those jets full of people as bombs with which to attack America, killing thousands in the process.
You would choose to allow that to happen so as not to infringe on the scum's "civil rights," their right to plan an attack on America in private?
Disgusting.
The suspected sleeper cells should be investigated with a specific warrant under the parameters of USC Amendment IV.