You know when you do something that is "not really hurting anybody" to get back at someone or some thing? Like a revenge on a pet-peeve? Sometimes when I get unsolicited "offers" in the mail, I return the postage paid envelopes with the original mailings stuffed inside so they have to pay the postage. If I hold the door for someone and they do not have the common courtesy to look at me or even say "thank you", I loudly say "You're welcome!" When groups of people walk down a sidewalk or aisle side-by-side and expect you to move out of the way, I shoulder check them then say "sorry." When I am trying to get off the freeway and the on ramp traffic is bumper-to-bumper, I just turn on my signal and start moving over between two cars, forcing them to make room.