From Brave New Worlds, 2nd edition,
edited by John Joseph Adams
(Note: This anthology originally appeared a few years ago but has been re-released with new stories as the first edition didn't get publicized well enough.)"Red Card" originally appeared in Fantasy and Science Fiction.
Anyone can shoot one person in Gilbow's society, so Linda Jackson shoots Larry, her husband. The town approves. She reports her act, turns in the Red Card that allowed her to carry out the act. Now that she's turned in her card, though, people don't have to like her.