Unless you are in a war zone, which USA is not, there aren't terrorists to find. USA soil is incrediy safe as a baseline, and all the security theatre doesn't stop anyone who actually tries. Nearly all the "wins" are entrapment of mentally ill people.
Yes, you're right. However, that's another issue. The question was "do terrorists take pictures of their targets?" and the answer is "yes they do". If the question is "are there terrorists in the USA?" then the answer is more complicated (I'd argue that shooting up an abortion clinic is terrorism), but in general the answer is "no". Should photographers be singled out for harassment? No, definitely not.
