Here are some of their answers:
1. When customers don't realize (or care) that you're carrying burning-hot plates.
2. The customers who treat restaurants like daycare.
3. Whenever diners say "Surprise me" instead of picking something out.
4. One word: "campers."
5. When people order burgers with all the toppings, only to later complain about them.
6. The customers who pretend they didn't like something just so they can get a refund.
7. The customers who snap or whistle to get a server's attention.
8. Customers who shove menus at their servers.
9. When adults ask for a kids menu.
10. Customers who don't even say hello before barking out orders.
11. The broken-glass clappers.
12. Entitled customers who claim they know the owner.
13. Last-minute diners who come in right before closing.
14. Entitled fellow restaurant workers who think they know better than you.
15. When customers complain that they have to pay for extra ingredients.
16. When customers claim they're allergic to something just because they don't like it.
17. People who don't tip on to-go orders.
18. And people who don't tip in general.
Note: Some submissions have been edited for length and/or clarity.