The worst that's ever happened to me was a coworker. And let's just say that a certain Grocery Store Company can go straight to hell for how they attempted to "deal" with the situation.
I was in training to be a supervisor at the time, kept coming across the same cart boy sitting on his ass in the cafe not doing anything. I knew I didn't currently have the authority to tell him to do his damned job, so told a manager.
She told him get to work, an hour later guess where he was again?
Told her again, she told him to go home if he didn't want to work. I was backing up the register lines an hour later (dude sat in our break room for an hour stewing about this I guess) he starts walking past my register, then stops at the end.
I turn to face him to see what he wants and he screams, "STUPID FUCKING RACIST WHITE BITCH" and chucks, full force from a foot and a half away, a full large fountain cup of soda and ice at my face.
It busted my lip wide fucking open. Security didn't even stop him at the door.
I won't go into what happened from that point forward because it still makes me boil with rage, but a month later he still worked for the company (in the same store) and I did not.
They refused to protect me. I should have taken their asses to court but I decided to just put it all behind me. I didn't feel like dragging out my suffering any longer than necessary.
So there we go. Coworkers are the real douche bags. Customers I can laugh off.