Cause I spent years working in a dental office...
I don't think cameras are something we really need, but policies of having more than one adult present for kids classes, etc. are all sound ideas and what we do at our dojo.
Do any of the major Aikido organizations have written policies on the subject of teaching minors? If not, it might be a good idea to put one together and get the major organizations to endorse and adopt them.
It's only a matter of time before an organization is taken to court for the behavior of a member of their organization, especially teachers that have received some sort of official teaching certification.
Many of the youth sports organizations have written policies and their coaches receive training. That makes it VERY clear when someone is acting beyond the pale, usually before their behavior can cross from the "grooming" stage into something more sinister.