I have given my landlord a key recently so that he can check the smoke alarm and take the water meter reading while I'm at work. I trust that he didn't install a hidden camera even though nothing could have stopped him apart from "being a decent human being" and "not wanting to commit a crime". Not every protection needs to on a technological level. I'd rather live in a society where we have other tools available than one where I have to take each and every matter into my own hand. This is what my analogy showed.