Life is imitating television on the Upper East Side, where an anonymous eighth-grade girl has founded a gossip Web log modeled after the one that is the backbone of “Gossip Girl.”

While on the TV show the fictional parents and school leaders appear oblivious to the catty Gossip Girl blog, the real-life provocateur, who calls herself Miss ITK (for Miss In The Know), has caused an incredible stir. School hallways are buzzing with the name of her URL; eighth-grade girls across the city are reportedly breaking down in tears, and, in the final climax, an unknown force has pushed the site offline.

Before it was shut down earlier this week, the blog had generated more than 300 comments, with some posters remarking on Miss ITK’s accuracy and others begging her to kill the blog, describing many tears shed and some friendships broken.

Miss ITK chronicled the social lives of what she described as the class of 2012’s “elite A-list.” One post described two girls’ attempts to revamp their images: one through eye-coloring contact lenses and another by dancing suggestively at a bat mitzvah. Another crowned a couple “our very own Queen and King.” Later, a post cataloged the class of 2012’s “A List” and “B List.”

Parents and students said the blog seemed like a deliberate copy of the one that is the heart of “Gossip Girl,” and whose author, Gossip Girl, narrates the show.

Like the television Gossip Girl, Miss ITK had her own signature salutation. On television, it’s “XOXO.” In real life, the line that reverberated with students was “Hello my butterflies.”

Miss ITK also mimicked the television show’s catty, metaphor-packed language.

“He fell so fast, even seventh graders won’t hook up with him,” one post read. “Now that’s GOTTA hurt. Dear Tommy, rip up those tickets to the top, because you’re headed on a one-way trip to the B-list. Love, ITK.”

Students greeted the site with surprise and dismay.

The father of an eighth-grader at a Manhattan private school, Jamie Lawrence, said his son was “shocked” by the blogs.

A Dalton 10th-grader said that, at the high school, students deemed the Web site “immature.”

“‘Gossip Girl’ is fiction. I think it’s kind of meant to stay that way,” the student said.

Speculation grew after the blog disappeared from the Internet, with teenagers saying the author had been expelled and that school administrators were responsible for shutting it down.

No one seemed to know the author’s name.

Administrators at Dalton and a handful of other private schools mentioned on the blog either declined to return phone calls or said they had no comment.

Middle-schoolers were the most affected. Writing on her personal blog, one eighth-grader said Miss ITK’s site is causing “turmoil” at schools across the city. Those named feel “victimized,” she wrote, while those not included “feel just as bad being left out of those A and B Lists.”

The gossip sites reflect new realities about the way young students are conducting their social lives.

Students and parents said online chat is ubiquitous, as is having a personal page on the social networking Web site Facebook.com.

Having their children living life online upsets some parents, who have attended seminars about safety, including one led by a Secret Service agent.

Students, meanwhile, are finding that their social lives can be disclosed in an instant — and as easily deleted.

The latter was the case for middle-schoolers at several schools across the city who were dismayed recently when their Facebook accounts were unexpectedly shut down.

“In the words of one of my friends, she said a little bit of herself died,” a Hunter eighth-grader, Simone Policano, said.

A spokeswoman for Facebook, Malorie Lucich, said accounts are disabled if students do not verify that they are above the 13-year-old age limit by joining a verified high school network.

Gossip also has a place on Facebook.

A feature called the “Honesty Box,” where friends can anonymously share confessions, is popular. So are online polls asking friends to vote on who is sexiest, most desirable, and coolest, the mother of an eighth-grade Manhattan private school girl, Lily Neumeyer, said.

Ms. Neumeyer said her daughter also uses Facebook to trade messages with a friend in the style of “Gossip Girl.”

“For example,” Ms. Neumeyer explained, “‘E — for Elizabeth — spotted on Fifth and 31st street, having a latte.'”

Ms. Neumeyer said she believes the forums are harmless when used maturely, and she is not planning to restrict her daughter’s access.

“You know when I was in school in high school, they used to do lists also,” she said, describing a memorable “Biggest Boobs” list. “They were just in pen and paper.”