Just make sure you are not taking "private recreational, non-communicative photography" as that is not protected under the First Amendment. Make sure you are taking pictures as a photo journalist, which is.
http://www.firstamendmentcenter.org/...irst-amendment
Article is too long to paste here, but it is an interesting and well cited article on what exactly does the First Amendment protect and not protect?
Photography pun aside, it is not black and white.