She helps herself

We have two shelves for customer requests at my library--the books are out on the public floor and are self-service, but the media is behind the front desk because our media is in locking cases, and patrons used to come pick up their requests, check them out at the self-service checkout, leave without getting them unlocked, and then get mad when they got home and couldn't open them. Recently the staff decided that all book holds for a particular old lady had to be kept behind the counter with the media because she kept grabbing them off the self-service shelf and leaving without checking them out.

I asked one of the old-timers if she was maybe just confused about how holds worked, and the old-timer scowled darkly and said "Oh, believe me, she knows."