shame: (noun) the painful feeling arising from the consciousness of something dishonorable, improper, ridiculous, etc., done by oneself or another.
Since many people today seem to compensate for their lack of common sense with their overabundance of laziness, I think it should be completely and totally acceptable to shame people into doing what is most common-sensical.
When someone at my office gets on the elevator on the ground floor and takes it up one floor, it should be absolutely fine for me to make a comment about their laziness and inconsideration for taking up space in the elevator and for making an extra stop when the rest of us have to go many more floors. (It should be noted that there is a lovely double staircase in the lobby of my building that is a nicer and faster way to go from the ground to the second floor and that the stairwells are nice and wide and full of windows and not at all dodgy and very nice to walk up and down when going between, say, the 7th and 8th floors.) I don't think the comments should be directed at the person; I'd rather pontificate to the packed elevator, "Wow, can you believe how lazy some people are? No wonder obesity is such a problem."
When I can't get on the streetcar because the back-door-challenges imbeciles of the world decide the front doors are the only way they can possibly exit. I have seen some streetcar drivers make comments, but not nearly enough. I'd prefer it to be deemed proper to ask the offenders, "Why are you incapable of understanding that passengers can only get on through the front doors and, therefore, you should not be an ignorant prat and should exit through the back doors?" No swearing, no threats, just ask them why they're dumb.
When two (or more) people decide the best place to stop for a conversation is in the middle of a busy sidewalk or right in a doorway. I'm actually working my way up to making comments to these idiotic oafs; right now I just glare and push. But really, why not? Again, no swearing or threatening or yelling. Simply comment on the situation in an attempt to shame the offenders into thinking a little clearer next time: "What makes you think it's appropriate to hold your conversation in the way of dozens of others? Would you stop dead in the middle of the 401? I hope you don't drive because people will die."
Those are the three big ones I can think of right now. I try to be patient, I really do. And I take things into consideration, like children and strollers and such. But really, people are just dumb and I think it's high time they know it. And, by all means, if I'm discovered to be such an offender, then I deserve to be shamed too.