The worst customer I ever served was a guy who walked into the grocery store and immediately started pissing and shitting everywhere on the floor. When anyone tried to stop him, he'd beat them up. He then decided it would be a good idea to take off all his clothes and act like nothing was wrong. I approached him and said "Dude, you need to put some clothes on right now". But instead of putting his clothes back on, he covered himself with snacks in the aisle. I walked up to him, grabbed him in a headlock and threw him out. Luckily that guy never returned to the grocery store ever again.