~ waves hand in the air ~
I know one! The trainer we had up at the big barn for two loooong years did that. She thought she was Very Clever. She thought that No One would figure it out.
She was arrogant and smug. And at times screaming and raging in emails and on FB. She “hid” some trail cams all over the place - I found one on the fenceline below the big barn, pointing down the hill at my barn apartment steps (attached to the smaller breeding and foaling barn) and truck. I found another one strapped to a tree that showed the lower (breeding) farm’s front gate - so she could monitor who was coming and going? The last stall cleaners that she ran afoul of up there pulled a camera off the rafters and another from the corner of the feed room when they left - and brought them down to the breeding barn to show me.
She had her other clients who were boarding there email and text the BO using their agreed upon words and accusations - nicely scripted. All about how awful the facility was (not) and how terrible the workers were (including me)… (not)
I went up to the house at the big barn where the trainer was living at the time (renting - cheap for this area) to collect some of the BO’s show clothes - at her request. I knew all those garment bags hung in the mud room between shows. I knocked. I politely asked for the garment bags. I stepped inside the kitchen and stayed at the door while TrainerB****FromHell went to get the bags. She came back - and started accusing me of something I had not done - some show pony had the wrong blanket or halter on - none of which was my job, but hers. She howled and stamped her feet. Mr. TBFH actually got up from his recliner and marched into the kitchen to scowl. I thanked her for the show clothes, deciding to just nod and smile and leave. As I was leaving, she yelled that I should never force my way inside her house again (she had let me in but this was a big show for Mr. TBFH). I stopped on the porch… slowly turned around and said "… and here is part of the problem. This is not your house. That is not your barn. That is not your arena. I stayed calm and waved at the red light on the cam she had installed by that porch as I left. I could hear her yelling as I went down to my truck parked by the arena and left…
So yeah… watching this case unfold has been very interesting. 
Speaking of boarding, I am sure that there was a basic boarding contract and releases that LK had to sign - as one would have at any equestrian facility… any “extras” should have been on a separate document.