"Do you think that putting suspicious elements under surveillance to combat terrorism is acceptable?"
Asked like that, I'm ok with it. Suspicious people should be watched. The problem comes when you are watching people for political purposes, or for "love" purposes. There need to be safeguards against abuse (for example, warrants). Because we've already seen abuses like that.
The sheer amount of people on the NO FLY list, and the battle that some take just to clear there name (few and far between), show you how messed the system is... you are possibly on a list, just for commenting on this thread