Foremost, I must point out how rampant courtesy really is. That was not a typo. Humans are phenomenally courteous creatures. Take just one example. Imagine a noisy tin box underground packed with any nonhuman mammal. Even if there were no violence, there'd be jostling galore. Now ride the subway in any major city (well maybe not Asian cities) and marvel at the many people who go in and out of them day after day and never even touch each other! But it goes way beyond that of course. Lines (queues) are so often respected that everyone notices when they're breached. It maybe be fashionable to decry the decay of courtesy, but any scientific look at the situation has got to acknowledge the refined rarefied heights of human manners. It's a whole another subject how courteous we really are, and how we got that way, but this is a tactical topic about making it even better, a tiny bit at a time.
Here's an example of bad Courtesy Terrorism. The driver behind you is tailgating. You tap the brakes just enough to flash the brake lights. When that doesn't work (and I don't confess yet to having ever done this) comes the tapping of the brakes enough to cause sudden slowdown, shocking the tailgater into backing off. Now this has a few qualities of good Courtesy Terrorism. It's a tiny dose of fear the perp will store in his lizard memory, at least making him more alert even if he doesn't tailgate less. But it is bad Courtesy Terrorism for one important reason: punishing the messenger. An accident is so costly in so many ways that the slightest increase in the risk of one has real negative value. Courtesy Terrorists should never suffer more than their victims. I believe this makes Courtesy Terrorism out of reach when motor vehicles are operating.
Now an example of good Courtesy Terrorism. In this case the motor vehicles were parked and idle. The setting, a bank drive-through in South Florida a few years ago. The lady in front of me parked in front of the teller window in her wide-ass buick, lobbed a smoking cigarette butt out her window and began filling out her deposit slip. Where do I start, right? Somehow I got the idea and the gumption in time to act. I got out, walked between her car and the bank, stood next to her open window and made a show of grinding out the butt with my shoe. Not too dramatic or threatening, but a kind of cartoonish exaggeration to my stamping and swiveling. She turned her blank WTF gaze my way. I smiled, wide and genuine (I was feeling good and smug) said nothing and walked back to my car.
This I suggest was a particularly clever Courtesy Terrorist Act. It had all the right ingredients. There was essentially zero incremental risk of injury or criminal or civil penalties to me or my victim. More important I think it may have actually done some lasting good. By invading her extended personal space in such an uncommon way I am sure she will remember it. The next hundred times she tosses her sot-weed stub out her car window she will be looking in the rear view mirror.