KNOXVILLE, Tenn. — Sup? R U on MySpace? No? OMG. TTYL!

If you have no idea what any of that means, you're probably not a teenager. But if you're a parent, you might want to pay attention.

Teens are flocking to Web sites such as MySpace.com that allow them to post photos, chat with friends, blog and meet new people. It's not all harmless fun.

At least three high schools in the Knoxville area have disciplined students recently for comments they posted on MySpace, although the students seemingly wrote the comments off school grounds.

"We've seen these incidents crop up all around the country, where students are punished for online comments that they make," said David L. Hudson Jr., a research attorney at the First Amendment Center in Nashville. "It raises some interesting legal issues."

Hudson, who has written several books and reports about students' rights and the First Amendment, said not all school administrators were unfairly punishing students for cyberspace conversations, but some are.

In January 2004, a few years after the Internet bubble burst, two techies from California, Tom Anderson and Chris DeWolfe, launched MySpace.com.

Put simply, the site is a network of personalized Web pages (some of them G-rated; others not). Fast-forward to 2006, and MySpace boasts around 52 million users.

Knoxville Catholic High School principal Dickie Sompayrac, said he punished five students for "derogatory" comments they posted in the fall about others on MySpace.

Sompayrac would not specify how he disciplined the students, what they posted or when they posted it, but he said it didn't matter if they wrote the comments off campus.

"If there were derogatory comments about another student on MySpace, we would not make a distinction between whether or not those comments were done at school or at home, since they are viewable to anyone who goes to MySpace," Sompayrac said.

As the principal of a private school, Sompayrac has more leeway with the law than a public school has, said Mark Goodman, the executive director of the Student Press Law Center, based in Arlington, Va.

Administrators at the public Powell High School recently suspended three students for posing as a teacher and writing inappropriate comments on MySpace, said Russ Oaks, spokesman for the district.

After consulting with the district's security chief, Steve Griffin, and the Knox County Law Department, administrators at Powell decided to suspend two sophomores and one junior.

Their suspensions varied, based on their involvement, from nine to 30 days, Oaks said. Did the school have the authority to suspend the students? Oaks said yes.

"It had an impact on the conduct in the classroom and the order and discipline in the classroom," he said.

The Knox County Sheriff's Office also investigated the incident at Powell. The information now is in the hands of the Knox County District Attorney General's Office, which must decide whether or not to prosecute the students, said Sheriff's Office spokeswoman Ashley Carrigan.

Brenton Thomas, a 16-year-old sophomore at Knox County's Central High School, logs onto MySpace every day after school to "get new friends, meet new people, talk."

He sends messages and photos to his older sister in Hawaii, and he peruses messages from strangers who want to be added to his list of "friends." The friend list - the bigger, the better - is the MySpace status symbol.

On this day, Brenton got a message from a user calling herself "Ms. New Booty." "Your (sic) so cute!! I like this pic! What's up? LoL," she wrote.

Brenton said he didn't worry about school officials looking at his page. "I never really thought about it," he said. "I don't have anything to hide."

The same goes for Gretchen Sutch, a sophomore at Knoxville Catholic who said she visits MySpace "every other day." She added that school officials shouldn't discipline students for what they write at home, she added.

"I don't think it's right for them to do that, if it's not on school time or school property," she said.