>Exploiting the Vault dwellers' naivety and lack of security, the Fiends successfully conned themselves into the Vault, upon which they killed the inhabitants and claimed the Vault for themselves.

>The Courier: "Can you tell me what happened to the residents here?"
Motor-Runner: "I guess it isn't a secret. Yeah, the residents of the Vault are all dead. We killed them. Funny thing is, they just let us in. We didn't have to force the doors or anything.
(Motor-Runner's dialogue)

How many prime vault pussies were ruined by Vault 3 hubris do you think?