Re: Faraday cage effect
A few years back the Mrs and I were playing with similar device over dinner, after a quick burst of "action" it must have slipped a little further inside and so it became impossible to switch it off again. A quick trip back to our room became necessary between courses.
A couple of other stories of the perils of otherwise of such toys. Before they switched to using bluetooth they didn't seem to have even the basic security of pairing, so any control would work any toy. A couple I used to chat with on certain forum used to like to go out to a pickup joint occasionally and the woman would then enjoy flirting and dancing with guys she fancied. One time they'd just bought her a remote vibe and thought it would add to the fun if the husband could play with his wife while she was being chatted up. They ended up at the bar next to another couple who looked like they might be there to play the scene too, The two women started chatting and then both suddenly jumped. Both their toys had gone off at the same time and both husbands denied it was them. Someone else at the venue also had a controller.
This was a well known problem at the time. One of the better known upmarket vendors of such things held a launch event for some bloggers who review things like vibrators. At that evening's do it soon became obvious to everyone that everyone was on the same channel. Hunt around the review sites and you'll find the stories.