Well, certainly the way the "victim's" parent tells the story, with the guy's camera being FULL of shots of little kids, it makes you wonder...but I wonder if the guy isn't exaggerating the camera's card contents, by a lot? If the guy was really just wandering around, taking nothing but pictures of kids, yeah that's differently creepy. Doesn't necessarily make him a pervert, and it's almost certainly not illegal...but it's creepy, and I wouldn't have wanted MY kids to be one of his photo subjects.
Still--tackling someone and beating the snot out of them for taking pictures isn't exactly cool, either. If the guy had actually threatened my kid or something like that--well, God help him if he threatened my kid!--but if it was just that he was taking pictures and it seemed suspicious, I think I'd have called the cops, then maybe gone after him to see if I could get a picture of HIM with my phone camera or whatever I had at the time, to show to the cops.
In today's world, it really just ISN'T always wise to be taking pictures of kids in public. But I gotta admit, I've done it from time to time, because they are just SO adorable sometimes. I saw these two little boys--brothers, I presumed--at the fair this year, standing watching one of the carnies blow bubbles and then trying to catch them. It was just too cute, and I took several pictures before I ever even THOUGHT about how it might look to be taking pictures of perfect stranger's children. BUT--if I'd been questioned by the police, my camera's contents would have revealed that kids were NOT the focus of my outing.
I try to be careful and think about how things like that could look to a parent--but I also get caught up in a moment sometimes, and because *I* know my motives are entirely innocent, I think nothing of it. I hope I never get tackled and beaten for it! But then, if the parent "caught" me taking pictures, I also wouldn't hurry off, I'd approach them and tell them what I'd taken a picture of and why, show it to them...and probably delete it if they weren't okay with it.