Junkyard’s story reminds me of the time in London when I saw a mail van toss a coke can out the window.. I rode up and tossed it back in. I can still see their shock as the coke splashed the dash.
Needless to say at the lights a big fat postie came waddling after me, shouting threats. I just kept riding slowly enough that he’d chase but fast enough to keep a distance. Most amusing watching him sweat his way down the street.
On a more positive note, one of my best encounters was with my wife on a singletrack in Provence. Two elderly ladies stepped off the trail to let us past, shouting “Allez, Allez!!”