Provoking an irate reaction seems to be largely the point. GrammarCop, one of several people who seem to exist on Twitter solely to copy-edit others, recently received a beatdown from the actress Kirstie Alley, to whom he had recommended the use of a plural verb form instead of a singular. “Are you high?” Ms. Alley wrote back. “You really just linger around waiting for people to use incorrect grammer? you needs a life.” (One of Ms. Alley’s people said that the actress was too busy to comment for this article.)

A life, indeed. While some of us may live to host weight-loss shows, others find solace in pedantry. Fans of the late journalist and linguist William Safire may recall his “Gotcha! Gang,” readers who liked to point fingers at the occasional lapse in Mr. Safire’s weekly language column for The New York Times Magazine. He once described them as “a hardy tribe obsessed with accuracy and a lust for catching error in others.”

Image Nate Fanaro tracks those who overuse their cap locks as CapsCop. Credit... Doug Benz for The New York Times

The same could be said of the Twitter gadflies, whose constant yipping at their victims gives a bit of an edge to the free-for-all dialogue on the site.

“There’s always this sarcastic humor pervading Twitter, where people will see something that someone has posted quite innocently, and they’ll respond to it in such a way that just is like a slap,” said Lance Ulanoff, editor of PCMag.com and a frequent tweeter. “Then what’s worse is that that gets re-tweeted, so now it’s like you got a bunch of people standing around you, pointing and laughing.”

Among the laughers and pointers is Jacob Morse, a 27-year-old user interface designer from Richardson, Tex. Last year, he and some friends started a Web site — Tweeting Too Hard — devoted to mocking self-important Twitter users. There, people can discuss fake-humble tweets like, “I gave my cleaning lady a raise today, even though she didn’t ask, as my own little contribution to fighting the recession.” Wrote one commenter: “Let’s hope she was grateful enough to overlook the bionic condescension.”