For the third time in one day, Palo Alto High School junior Olivia Diamond logged in to Facebook. She clicked on her inbox, read two messages, ignored the first one and skimmed the second one. She checked notifications. The first two were junk mail and the rest were "wall" posts. She scanned her wall (where friends leave messages), went back to the home page, read about what her friends have been doing through her mini-feed, looked at the Facebook chat — 88 of her friends were on — decided not to message them and logged out.

Her Facebook browsing took a total of five minutes, which she typically repeats two to three times a day — plus the hour she spends on it during homework time.

"It's basically where everyone goes when they're supposed to be doing homework," she said. "Around 9 (p.m.) you'll see about 200 people in the Facebook chat."

On the Facebook website, Diamond does what most students do. She shares pictures, funny YouTube videos, inside jokes through wall posts and so on. But from time to time, she sees her peers' catty remarks, revealing photos, offensive groups and expurgated status reports.

For students, Facebook is a social food, a necessity, an indulgence. Sometimes it is a mirror world of their face-to-face social interactions and at other times it is a public diary, a domain for uncensored and often anonymous expression.

It can also be a battleground, however, a place for conflict and intervention between peers, between users and Facebook administration, and between students and school officials.

There are 1,321 people in the Paly Facebook network and 2,346 people in Gunn's. Students not only connect with friends through it but also complete homework assignments and form study groups. Paly journalism and science departments use the network to aid in research. The administrations at both Paly and Gunn use Facebook to coordinate with leadership students who notify the student body about upcoming events and more. Teachers are creating Facebook accounts and "friending" students.

Parents are registering and even "friending" their children — in large part to stay familiar with their children's social lives, although some children feel that this is a breach of privacy. Many parents, however, are left in the dark wondering what their children are doing online.

What parents would see might cause some to worry.

According to students, the "status updates" that teens post on Sunday mornings sometimes allude to parties and underage drinking that happened the night before. The comments come with pictures from the previous night: students sitting around a table drinking Coors Light and playing a card game; students with an open bottle of Jose Cuervo at a local restaurant; students taking shots, pouring handles of vodka and smoking bongs.

Comments posted about these parties and what goes on at them can be revealing and almost crude, students said.

The brunt of defamation, however, shows up in "Gossip Girl"-type Facebook groups. The groups are based on the Gossip Girl novel series that includes blog excerpts written by "Gossip Girl," who dishes the latest rumors and happenings related to characters in the book.

In the Paly network, there are groups such as "Gossipa Girlio," "Gossip Gangster," "One last Appearance ... Maybe" and "La Bonne Vie." Each group revolves wall postings by the page's creator about the recent drama and rumors, along with confirmation and denials from student members.

On Gossip Gangster, a student wrote "We all know so-and-so looked like a s--- last night," according to Diamond. On La Bonne Vie someone wrote that Diamond was pregnant.

Surprisingly, she said she was not offended and did not respond because the rumor was "obviously false"; however, she did want to find out who was the creator of the group.

Paly junior Malaika Drebin characterizes the Gossip Girl websites as typically saying: "Who got caught by their parents for being drunk, who was in a girl fight, who threw a party and if it was lame and why it was lame, who had a party crashed, who hooked up with whom.

"Sometimes people write, 'That so didn't happen. Get your facts straight.' Other people write, 'It did happen.' People get really mad about it. It is horrible, but some people want to be mentioned in it. They get a lot of attention from it.

"I don't think anybody doesn't use Facebook because they'll be gossiped about," Drebin said. "Even me, I'm still part of the group, even though it is unethical and in so many ways catty. Otherwise, I'd be out of the loop. There is gossip, and then there is gossip on Facebook where everyone hears about it."

Despite the prevalence and persistence of backbiting, some posts on the gossip websites get deleted either by the group founders themselves or by Facebook staff. Most of the posts on Gossipa Girlio and Gossip Gangster have been deleted.

"It got vicious," Diamond said referring to Gossipa Girlio. "Most of (the group administrator's) friends found out about it."

For the most part Facebook, as a company, depends on user discretion to eliminate harassment on the site.

"We rely mostly on our users to report content that violates our terms of use, and we have a dedicated team that reviews these reports," said Simon Axten, Facebook's privacy and public-policy spokesperson.

Under the terms of use, Facebook participants agree to not "upload, post, transmit, share, store or otherwise make available any content that we deem to be harmful, threatening, unlawful ... or otherwise objectionable."

"We also delete photos of underage drinking and drug use and have an escalation procedure for more serious reports of abuse," Axten said. "These mostly involve threats of imminent danger."

As for people creating accounts using pseudonyms, such as Gossipa Girlio, Axten said the company has systems in place that make it hard to create and maintain bogus accounts.

"We have a blacklist at sign up, for example, that prevents people from registering with dubious names, and we flag suspicious or anomalous activity so we can investigate further and take action as necessary," he said.

Nevertheless certain groups, such as La Bonne Vie, whose name is less obvious than other gossip groups, has been on Facebook since July 6. La Bonne Vie has 123 users.

Under "activities" the site reads, "Remember, you are Nobody until you are talked about. XOXO you know you love me ... GOSSIP GIRL," similar to the Gossip Girl novel's blog.

On the group's wall several posts have been deleted. One student wrote, "Once again you got your (information) wrong. Surprise, surprise, surrender yet?"

While controversial content is eventually removed from rumor pages, other Facebook postings are uncensored.

The application called "Honesty Box," which was created by a third-party developer for Facebook and launched in June 2007, allows students to post comments about someone anonymously and often times anomalously.

One Paly student's honesty box comments read:

"You're beautiful."

"You're starting to gain a little weight ... aren't you."

"Control freakkk, don't judge, don't hate, be nicee."

"You're so pretty."

"Everybody hates you."

The student said she didn't care even if the comments were abrasive because they were what she expected from adding the application to her home page.

Gunn High School senior Libby Craig, however, decided not to add the application to her Facebook.

"People sometimes write mean things," she said.

She also chose not to add other applications that allow students to compare others against each other.

"I don't want to add applications that rank people, it's just pointless," she said. "People shouldn't need that to feel better about themselves and conversely you don't want to feel bad about yourself. It can be really hurtful. There are mean comments, testimonials. It will show that 'This person is the hottest,' and then someone can write, 'OMG, that's so not true.' It's anonymous. It's really hurtful and not true."

The targets of catty comments aren't just fellow students. Administrators receive their fair share of negativity.

Gunn students joined a group called "Mr. ----- is a douche." Paly students joined groups about their teachers such as "Ms. ----- is impossible to understand," and "Mr. ----- is my comrade!" — a forum in which students comment on the quirky habits of their teacher.

Some Facebook groups protest school policies. At Paly, groups formed to protest Principal Jacqueline McEvoy and her administration's policy changes over the last year and a half, such as "Stop McEvoy," "J Mac is Hella Wack," "Official Petition to Change the Paly Bell Schedule," "Critical Mass" and others.

"Critical Mass," which started in the spring of last year, is still up and running. It has 256 members and features a picture of McEvoy with a red line through it.

The group states its goal as: to protest and "do things that will (anger) the Administration but that they can't punish us for, like calling them by their first names and such."

The group aspires to change numerous policies, including the daily school schedule so that it starts later, the dance policy that bans "freak dancing" and makes "breathalizing" mandatory, the skateboarding/bike policy (although it does not specify how), and the policy that requires students take the STAR test as a prerequisite to advanced-placement (AP) courses.

The description of the group says, "We want Jackie to ... leave this town." Below the description, the text reads: "This is a SECRET group: The group will not appear in search results or in the profiles of its members. Membership is by invitation only, and only members can see the group information, the discussion board, the wall, videos, photos and posted items."

Despite it being a "secret," though, all it takes is one member to show the group to Paly administrators and the secret is out.

"Students don't understand that Facebook isn't as private as they think it is," said McEvoy, who is aware of the protest groups. "There can be no assumption that Facebook is private."

In response to the activities of Critical Mass, McEvoy said the group has had little effect at school. She said she only received about five e-mails from students saying they wanted to change policies at Paly.

"There may be 600 people in a group, but when people are silent, they are simply silent," McEvoy said.

She added that the best way to change school policies is to talk to her directly.

Paly senior Noah Sneider was also dubious of the groups' effectiveness.

"I don't think anything has really come out of the (Facebook protest groups). It's not like the school has changed policies as a result of a Facebook group. I don't think they particularly care how many people join Facebook groups in terms of the policies they make. Really it's just 'clicky.' Students click 'yes' and then nothing comes of it. It's not like there's any larger organizational mechanism behind it."

McEvoy said she does not have a Facebook account. But regarding personal attacks, her philosophy is: "If people want to say hurtful things, I can't control that. They have to ask themselves how they would feel if those things had been written about them."

But that doesn't mean comments can be posted with immunity. While McEvoy views Facebook as a domain for free speech and takes students' criticism as part of her job, she said, "Students could be suspended or expelled based on what's on Facebook. Ongoing harassment can be expellable even if marked private."

Students are allowed to use Facebook at school. But administrators could suspend students for making threats or posting obscenities or any other messages on Facebook that violate a student's or teacher's rights — especially if the activity occurred during school hours, according to McEvoy.

Most of the time, when the administration sees evidence of harassment on Facebook, the user has printed the information out or given the administration access to their profile.

Still, school officials cannot always trace harassment, especially when it is anonymous or the evidence is deleted before the administration can intervene.

Like McEvoy, Gunn Principal Noreen Likins wants her students to be aware that what they put on Facebook is in the public domain. While both principals have no desire to go on Facebook, respecting their students' rights to privacy, they will make exceptions.

"Facebook, if it's impacting the learning environment, then we will tackle it," Likins said. "We've had numerous instances where Facebook spilled on to campus. Anything that constitutes harassment, we're going to do something about it."

Even though Facebook is a relatively new tool, the principals recognize its influence, and likely staying power.

"It has become such a fabric of the world that you can't ban it," McEvoy said. "It's done some really positive things. It's created critical thinking even with Critical Mass. The students are thinking about positive change."