Personally I like that analogy because it was recently revealed that people can 3D print working keys from a photo of a key. So even the "physical" key is vulne

Personally I like that analogy because it was recently revealed that people can 3D print working keys from a photo of a key. So even the "physical" key is vulnerable to security attacks of a digital nature. All someone needs to do is get a photo of the global "key" and they can then get into anybody's safe.