Agree with everyone else. Totally misleading headline. It’s not my iPhone or watch that’s a privacy nightmare.
As to your bathroom picture… you could do that, I suppose. Though I’d think that the iPhone propped up on the counter with the camera pointed at the shower would be a bit obvious.
iPhone in the ceiling? Go into your own bathroom, check out the ceiling, and then come back and tell us just how you’re going to place your phone inconspicuously in the ceiling with the camera poking through. Better yet, take a picture.
Oh. A public bathroom. Right. Because you’d definitely want to put a device with a unique serial number and cellular plan in a place where it can be found and traced back to you.
As others have said, much easier to buy a small, cheap dedicated recorder.
Nightmares? Nope. Hardly even a troublesome daydream.