I saw some time ago a review on another board where some %6$&** ass used a phone camera or some other device to record a visit. I was dumbfounded, hoped it was just a boast but it takes all kinds. I hope your warning will prevent this in the future.
Again this same thing happened to a client on the same board and it was used against him in some manner. He was short in his explanation of what happened but it was clear that his neighbors had been shown some of these photos and he felt that he had to give up reviewing.
Perhaps others who have some technical expertise can weight in and give some advice to protect, prevent or limit this sort of crap from happening.