A lot of large orgs have a very distributed decision making process where decisions are made far outside of a specific chain of command. Frequently it's unclear

A lot of large orgs have a very distributed decision making process where decisions are made far outside of a specific chain of command. Frequently it's unclear who you are even supposed to call to verify the identity of someone that just shows up. It may take awhile to even reach the right person and while you are making those calls you aren't doing your work and you are delaying the service this unknown person is theoretically there to provide. What if this person is there legitimately, you piss them off or deny them access, and then you get an angry call from someone several levels of hierarchy above you blaming you for slowing down their project? No bueno You also can easily end up with a version of the bystander effect; if someone is here than SOMEONE in the company must have validated them etc. In orgs I have worked for in the past it would have been trivial for me to show up with tools, claim to be from IT, and be given access to whatever I wanted immediately.