The biggest mistake you've done in public?

I regularly deface bathroom stalls, but that's not in public..

When I worked in retail, whenever there would be a customer with a young child, I would stare the child down when the mother wasn't looking, just to see if I could make them cry or react to it. Toddlers would always hide behind their parents legs. One time I did it to this cart full of Mexican children (like 2 babies and a 3 or 4 year old). Shit was funny.