What are some unsanitary things you have witnessed while working in a restaurant?

The bowls that coffee creamers go in don't get rewashed unless they have noticeable smudges of food, and then fruit is put in them for the next customer who asks for a side of fruit.

The milkshake cups NEVER got thoroughly washed because the liquid was very thick. Everytime I had a customer order a milkshake, I would scrub a milkshake cup vigorously in the utility sink with soap and uncomfortably hot water. I was the only server who did that.

IHOP servers would prepare salads by grabbing fistfuls of lettuce without washing their hands or wearing gloves. Many of them wouldn't even wash their hands after taking dirty dishes to the back.

I work in a Mexican restaurant now. The only thing I find unsanitary about it is the amount of flies that live in the kitchen during the summer. The restaurant has outdoor seating, and the doors to outside are wide open for 11 hours everyday in the summer.