Something almost exactly like this happened with me and my foster daughter and I was so close to completely losing it. Snatched his camera off of him (it was a big expensive camera, not a phone) and started yelling and screaming him. Whole crowd was either silent or acting like I was the bad guy and trying to get me to calm down, but no one would go near me either cause I was giving off crazy energy. My daughter was freaking out too and was REALLY mad at him. NO ONE other than myself and my daughter were calling out the guy who took the pictures. Motherfukker's entire family come up cause we were causing a scene and they were all defending him, his grown son saying the camera was on "burst mode" and it was an accident and that's why 20 pictures of my daughter were on the fukking memory card. I can't even describe how fast my heart was beating in that moment, that was probably the closest I've come to losing control in public.
In the end I knew I couldn't beat the shyt out of him or bust up the camera or I was the one who would be getting the cuffs, what he was doing wasn't even illegal or anything. But I couldn't let him get away with it either. So I popped his memory card out and snapped it in half. I just hope he was eternally shamed in front of his whole family but for all I know they already knew he was pulling that deviant behavior.