How is handing over your key to the guards worthy of note? Is it because this isn't a hotel? In Britain and Europe I've frequently encountered the rule that hotel guests are supposed to hand over their key at the front desk whenever they leave the hotel. We don't do that in the States.

I attended a large university, not a small liberal arts college, though I've worked at some. All I can say that sounds relevant is that the size of their campuses can vary tremendously.