NEW YORK - They feel her pain. At the Spence School and Greenwich High and Fullerton Union High and Nyack High and Narragansett High, teenagers and near-teenagers, hundreds of them, are waving a virtual flag for Tess Chapin, a 15-year-old from Sunnyside, Queens, who has been grounded for five weeks. A few days after founding the Facebook group - “;1000 to get tess ungrounded”; - Tess had nearly reached her stated goal, with 806 members by Friday morning; after this column about her quest was posted on nytimes.com, she surpassed it.

This is teenage rebellion, electronic style - peaceful, organized and, apparently, contagious.

So basically, Tess explains on her group page, she made an honest late-night mistake. Her parents flipped, and they grounded her for five weeks - “;thats my childhood right there,”; she wrote. “;please join so I can convice them to unground me. please please please.”;

On Monday, the official start of what Tess calls her “;groundation,”; she circulated a petition during sixth period and after school at Millennium High School in Lower Manhattan, where she is a sophomore. At a friend's suggestion, once she got home, Tess put the petition online by starting the Facebook group, which she categorized under Organizations: Advocacy. The group promptly took off, proving that no adolescent experience, in the age of social networking, is too small to start a movement.

Tess was grounded for what all parties confirmed was a first offense of drinking at a party and missing her 11:30 curfew by an hour. Why five weeks?

“;Her dad wanted to give her three months,”; said her mother, Jennifer Iselin Chapin, a fundraiser for the Natural Resources Defense Council, an environmental group. “;I wanted a month. This was a compromise.”; For the duration, there will be no parties for Tess, no sleepovers, no Sweet 16s, no hanging out at a friend's, and certainly no hanging out at a party where there is no parent present and possibly alcohol served, like the one that landed her in this situation in the first place.

Tess originally invited around 1,000 people to join her group, and by Tuesday, 500 of them or their friends had signed up. By Friday morning, the number had surpassed 800, and Tess said that she recognized only about 35 percent of the names. “;Have never met u but I pledge to make a statement so I hope this works,”; wrote a young New Yorker named Ethan Bloom, in a typical sentiment of support displayed on the Facebook group's wall, a public space for messages.

There are, of course, dissenters. A range of parenting philosophies have emerged on the wall, turning it into a mini-forum on child rearing, 2010.

“;If your parents didn't care,”; pointed out a sophomore at Ithaca College, “;they would have just let you rot.”; Someone agreed with Tess that “;parents can be stupid.”; A friend of a friend expressed hope that she and her parents would take something “;grand”; away from the experience. A close pal chimed in, “;I love you, but your parents are not gonna unground you for convincing 1,000 people to join a group.”;

It is to this last theory that Iselin Chapin subscribes.

“;What's your fallback strategy?”; she asked her daughter on Thursday night, sitting across from her in the living room of their two-bedroom apartment in Sunnyside.

“;OK, one: drive you so crazy that you're going to unground me,”; Tess replied.

Her mother shook her head. “;That's not going to do it, sweetheart.”;

Tess, who is active in her school's environmental group and struggles a bit with math, was full of fast-flying, impassioned arguments: how much genuine remorse she had already expressed, her inalienable right to the pursuit of happiness, other parents' more lax standards, the injustice of so heavy a punishment for a first-time offense.

Has Tess been like this since the groundation started? “;She's been like this since she was 18 months old,”; her mother said.

In the earliest version of this column online, I suggested that it was tempting to form a Facebook group called “;1000 to Support Parents Who Believe in Consequences for Serious Lapses in Judgment and Care Enough About Their Kids to Enforce the Rules.”; Within hours, a reader did just that. Even parents who might have come up with a milder sentence could at least express their support for those who make them look like reasonable creatures, comparatively, to their own children.

One of Tess' friends suggested, on her wall, that she “;jst leave!”; But Tess, so far, seems to have accepted her fate, albeit with grumbling and the same charming sass that she displays on Facebook. She does not have any plans, it seems, to skirt the punishment, at least none evident from her Facebook group's page. Click to find out about events relating to it, and up pops this boilerplate: “;1000 to get tess ungrounded does not have any upcoming events.”;