What’s the craziest or most outrageous (maybe even NSFW) incident that led to someone being fired from your workplace?

Surprisingly this one actually didn't lead to someone being fired because the person was never found, but when I was a teenager I worked at a local retailer in Canada called Canadian Tire. The manager called everyone into the employee washrooms to show us that someone had scrawled "CT sucks" in human feces -- presumably their own -- on the inside of a toilet stall.