This winter, teenagers at a Chicago high school used their Xanga websites to post obscene and threatening comments about a teacher, in one case suggesting her neck be "slit like a ... chicken."
Last spring, a girl at a different Chicago high school outraged students when she posted derogatory comments about gay marriage and blacks on her Web log.
The school district dealt differently with the two situations, defending the girl's freedom of speech in the latter while reportedly disciplining the three teens in the first.
The incidents speak not only to the murky territory of free speech in schools but to the challenges of educating in a cyber age - particularly with the growing presence of Web logs or blogs, those online pages that millions of teens use for journals, photos, dating, or chats.
The worries range from the serious - student safety and cyberbullying - to the mundane, minimizing gossip and protecting students from embarrassment. Some schools are trying to restrict access to the sites, or are holding sessions to educate both parents and students on proper guidelines.
But drawing a line between free speech and misuse can be tricky, and blog proponents caution that there are plenty of positive ways to use the medium.
"We're a little quick to respond in part because this is such a new phenomenon, and it involves the Internet," says Steve Jones, a communications professor at the University of Illinois in Chicago. "You can't blame school administrators for being fairly sensitive about these things. What's happening is that in so many domains in our professional and personal lives we're having to reestablish some boundaries in regard to the Internet."
Blogs are still unfamiliar to less computer-savvy adults. But a recent study by the Pew Internet & American Life Project showed that 1 in 5 kids between the ages of 12 and 17 - about 4 million - keeps a blog. About twice that many regularly read them.
"It's replaced the mass e-mail or even the phone chat," says Amanda Lenhart, one of the researchers on the Pew study. "They use them to reinforce the connections they have."
Few teens refer to the pages as blogs, says Ms. Lenhart, calling them by their brand names - Xanga, MySpace, LiveJournal, and Facebook are the most common. And some experts say blogging is a misnomer since, rather than keeping journals, the teens are engaging in social networking.
Go to a site, find a school, and click randomly on a few names - michizzle, PaPi chULO, Swimmer4Ever - and a world clearly not intended for adults emerges. Girls talk about their ideal guy and post provocative photos. Profanity and cyberslang are rampant. Kids discuss parties and alcohol, the teachers and other kids they hate, or engage in inane chats: "How R U? I miss u gurl."
"The key thing is that young people appear to be totally oblivious to the fact that everything they post in these sites is public, permanent, accessible from throughout the world, and easily transmittable to anybody," says Nancy Willard, director of the Center for Safe and Responsible Internet Use in Eugene, Ore. When adults read the sites, "teens argue that you're invading my privacy," Ms. Willard says. "That's just the point. It's not private."
Some kids use blogs for class assignments, thoughtful journals, or outlets for creativity. The worries come when teens post too much personal information - their real names, addresses, e-mail, schools - not realizing it is also available to stalkers or child predators, or when they use the sites to pick on other kids, reaching more people than old-fashioned bullying ever could.
"Kids used to pass notes around in school," says Parry Aftab, director of Wiredsafety.org. "Now they're putting it onto pages with 42 million users."
Deborah Finlay, guidance director at a middle school in Virginia, first tuned into the dangers when a student committed suicide and cyberbullying appeared to be a big factor.
Now, she and other guidance staff conduct regular "netiquette" sessions with every class on safety and bullying and also educate parents. "The parents in many cases are just as naive as the kids," she says.
Bernard Piel, a history teacher and assistant to the dean at Norman Thomas High School in New York, recently talked to a student who posted provocative photos. "I want you to imagine that you're 24 years old, you're trying to get a job somewhere, HR does a background check, and these things come up," he told her.
It's a question few teens think about. Posting publicly "is online attention-getting," Willard says. "They become the stars of their own reality TV show."
But some students say it's more than that.
Sergio Barraza-Valdez, a sophomore at Exeter in New Hampshire, uses his LiveJournal page for a very personal journal.
"It's helpful for people to know what's going on, if you're having a hard time getting through something, and you kind of don't want to tell someone but you kind of do," Sergio explains. "And it's nice when people leave comments being supportive."
Over his winter break, Sergio's stepfather died and a good friend from home committed suicide. Writing about it - and getting support from his scattered friends - was a good outlet, he says. "People understood when I came back what had happened."
Still, Sergio says that learning what to write and what to keep to himself has been a trial-and-error process. "I misused it a lot, last year especially. I wrote really mean things about people," he says. "It's easier to let out your emotions instead of keeping your cool like you would in person."
That blogging could be a positive social outlet was hard to understand until kids explained it to her, says Ms. Aftab, who trains teens and parents to be Internet safety leaders. "One girl told me, 'I'm new to the school, I'm shy, I'm not the prettiest girl, but I go on great vacations... If the other kids find out how interesting I am, maybe they'll be my friend,' " she recounts.
To give them a safer outlet, Aftab has helped develop a new site, YFly.com, which will launch in February - designed solely for teens. "If I find anybody over the age of 18, I have permission to call the cops," says Aftab.
In the meantime, schools are reacting to the blog challenges as best they can. Many outlaw use of the sites on school computers - though kids find ways to get past the filters. Schools have a harder time controlling what gets posted at home, even if it has a tangible effect within school walls.
"If a student is identifying an individual, or making a statement that threatens violence, that's a different kind of speech than something we might consider vulgar or offensive," says Patrick Rocks, general counsel for the Chicago Board of Education. "There's no bright line. It's more of a continuum."
A few private and parochial schools have tried to ban use of some blogs even at home. But experts say schools are on shaky legal ground, and some face lawsuits. One Pittsburgh senior is currently suing his school district on free-speech grounds, with the help of the ACLU, after he was suspended for parodying his principal on his MySpace site.
Aftab suggests establishing a policy at the beginning of the school year, which outlines acceptable Internet use and disciplines students who violate it. "Then it's a contractual issue," she says.