I don't know if you are arguing that my tactic hopes to work through humiliation or not, but I would argue that it does not. I'd say that it works because it's a pain in the ass to scrape a sticker off the dead center on your field of vision on your car, which sounds like a consequence. I will say that my tactic has been 100% effective with only one application on the scofflaws I walked by a few hundred times before I started my campaign.
I am not on a one man campaign to stop people from parking on sidewalks across the world, nation or my city. I adresse my audience one person at a time, working mostly in my own neighborhood.
I wonder where you get the idea that vigilantism only gets short term "attention" (whatever that means)? Do you think that it's wrong for a single person to try to cause positive change in their direct environment during the time they are in it? Sounds like that at least. Why do you think my advocacy is unfair and unreasonable? I think it's fair, reasonable and working.