Engineering company with one big shared drive with a simple file folder structure. Drawings were in a folder with a text file up top that said something like “do not modify without Ed’s approval”, Ed being the senior most engineer. Everyone was given the same access levels to read/write/modify, but because the note said not to, no one did. (They totally did change files without Ed’s approval).
We had some work that required being authorized to work in the US and one project where we had to be a US citizen, not just green card or work visa or whatever. The check? None, you got default access to the entire drive unless you had an accent. I only ever saw people with accents get questioned about their citizenship.