The real people you have to worry about are not the ones taking pictures. They are the attendants, because those are the ones that can set themselves up to be alone with the children. And they are not going to be taking any pictures at this point.
This is just an excuse. The real reason they do not want people taking pictures is that they do not want them posted on YouTube. Because the ones that end up there expose what a waste of time going to these wastefests actually is, and people will simply decide that the religion is not for them once they realize children are pushed to pio-sneer as their "career".