The one case I have heard of where a woman was photographed while in the stall, was by a man, dressed as a man, not a transwoman. And the only other story I heard of was a Transman was attacked in the mens room by, a man. Go figure. It isn't Transpeople who do these things, it is cis-men.
There are perverted people out there, but it isn't the Trans community. It is the cis community.