I lock my door to control access. Physical barriers aren't meant as a way to prevent access but as a way to control access. A locked door means that those wit

I lock my door to control access. Physical barriers aren't meant as a way to prevent access but as a way to control access. A locked door means that those without the required permission shouldn't pass. If they do pass you immediately know they are unauthorized and can treat them as such. Locks also keep honest people honest. Sometimes temptation and curiosity are too much.