I can't give a complete answer, but in the US there is a notion of "expectation of privacy"—you're not allowed to film (or watch in person!) where someone has a

I can't give a complete answer, but in the US there is a notion of "expectation of privacy"—you're not allowed to film (or watch in person!) where someone has an expectation of privacy. This definitely includes changing rooms and bathrooms. Does it include the bedroom of a rented house? Probably. The living room? I don't know, but you could probably argue that. A cube farm in an office building? No expectation of privacy. That creepy-ass camera (can't find a link) under employee desks, pointed at their chair and coincidentally at their crotch, to track whether they're at their desk? Almost certainly violates expectation of privacy, because crotch-shot. Anyway, that's one of the search terms you'll want to use if you research this.