While it's not necessarily a deterrent, it's definitely a concern, if not a nuisance. I was once sitting quietly in a bar once when I saw two giggling girls pointing a phone at me from 30 or so feet away. I covered my face with my fist, giving them the finger. On another occasion, I was leaving a museum and while I was going down the steps, I had a funny feeling, so I let the guy behind me go by and sure enough, he was holding a phone which happened to be in cam mode.
While I have come to terms with the fact that some folks see us as a novelty (and a humorous one at that), I do my best not to show my face, which is I usually have a pair of sunglasses on hand when I'm out and about en femme.