bmattock
Veteran
Your use of "often" tells us that sometimes the danger is real. How do you tell the difference before "damage" is done?
It would be difficult, if not impossible, to determine all risks that will result in actual damage. The concept of prior restraint is anathema in the USA except under the most extreme of circumstances (not to be confused with 'Prior Restraint' as a legal definition, which applies to publications).
This is part of the downside of living in a free society, where no one's liberty is restrained on the basis of what they might do wrong, but only if they have indeed done something wrong. It is not the best of worlds for a victim, who has then been injured, but how would it be if we imprisoned people based upon their likelihood to commit this or that offense (using whatever futuristic method might be imagined to do so).
With regard to parental vigilance and photography, I have no objections to parents keeping a very close eye on photographers who appear to have an interest in photographing their children, nor even with parents who approach and question a photographer who is taking such photos. I draw the line at demands to see the photos, delete the photos, leave the area, stop photographing their child, etc. I am happy to await the police if they wish to call for them - or I'll be happy to do so myself.
Parents have the right and the responsibility to protect their children from danger, but not danger as they perceive it. Since prohibiting a photographer from photographing their child in public is not legal, if they still feel there is a real danger, then their responsibility is to remove their child from public view.
Parents have the right to protect their children. That does not include the right to require others to modify their legal activities to make the parents feel better.