Patron pet peeves

Let's start a thread of patron pet peeves - this is for little things that get on your nerves, not things that break rules of conduct/should result in exclusion! At my library, we have an adult patron who comes in nearly every day and stays all day (fine), always has the maximum 50 items on hold (fine), requests lots of childrens materials (fine), never checks anything out but just uses materials in-branch (fine), and multiple times a week cancels and re-places all of his holds to extend their time on the holds shelf (extremely obnoxious!) He creates so much extra work for staff, who have to pull and check in all his holds to print updated slips for things that have often only been on the shelf for a day or two to begin with (we keep items on hold for a week). It drives me NUTS!! At least wait until the day they expire!! So, what are your patron pet peeves?