Presumably, everyone on the entire campus is trusted to be there, with increasing layers of security. There are guards posted at all entrances to the campus, where I have to present a badge + window sticker to get on. Once on campus and parked, a swipe card gets me into the building, where I am presented with an X-Ray machine for my belongings and a metal detector that I have to walk through for entrance.

If I am taking any property on or off campus, I have to also present a property pass signed by someone with the authorization to allow that activity.

Admittedly, I could probably sneak a flash drive on if I were so inclined, but that's probably why they do background checks on people before they're given badges and swipe cards and all that.