From vengeful schoolgirls to predators and sophisticated scammers, social networking sites are increasingly being used to wreak havoc on users' lives, web safety experts say.
For teenagers, the news gets worse. If it's not a sexual predator or an identity thief snooping round your online profile, it could be mum or dad.
Kiwi parents are joining networking websites such Bebo, Myspace and Facebook, for the sole reason of spying on their kids.
Rachel Harrison, of internet safety group Netsafe said parents were becoming more familiar with the technology that made up a big part of children's social lives. Recent cases of identity theft and cyber-bullying had parents worried, some resorting to checking their children's Bebo pages, she said. "A lot of people provide too much information online that can be used against them."
She said "surveillence mode" wasn't generally necessary, but it was important that children had an adult to turn to if something went wrong. It helps if they know what Myspace is."
Harrison said NetSafe received four to five calls a week regarding identity theft. Most involved teens, and the theft was generally designed to humiliate or degrade.
In one case, reported by Kiwi children's magazine Upstart, a 12-year-old Wellington girl had her Bebo password stolen by a "friend" who then posted nude pictures of a woman's body on the girl's page with the words, "Want to hook up? All the boys at my school LOVE ME. You can too."
Sydney-based Andrew McKee, of security software company Check Point Technologies said people were commonly lax with personal information on social networking sites. Anyone who used the sites should take care with the information they posted.
"What you wouldn't share with a physical stranger, you shouldn't share online."
Details such as birthdate and address could be used to set up bank accounts, credit cards, or phone accounts, he said.
Harrison said many young people already knew how to get rid of a false site about themselves and how to make use of networking sites' "block abuse" functions.
She pointed to a website called Zoominfo, which gathered information from all over the web, as an eye-opener to the "digital footprints" we leave.
"I entered our executive director's name [Martin Cocker] and it came up with two listings for him - neither of which he knew about or had anything to do with."
With International Privacy Week kicking off on August 26, how do teens rate their risk? Lucie Irwin Whitney, 15, an Auckland Girls' Grammar student uses Bebo and Myspace. She told the Herald on Sunday her parents knew about her pages, but she'd be be "pretty mad" if she found them spying.
"I would remove some posts and comments unless they didn't 'find/add' me. I probably wouldn't let them be my 'friend'. That's why I don't keep much dirt/personal stuff on mine.
"Other people put all sorts of things on their pages, so I guess they're hoping or guessing their parents won't read it."
Sarah, 17, a St Cuthbert's College student said her parents probably wouldn't know what Bebo was. She didn't worry about stalkers or identity theft and made use of the site's security settings.
"I don't have the personal details on the page, I just use it to keep in contact with people."
Bebo, MySpace, Facebook. Bells failing to ring? Chances are you're over 30 and don't talk to teens, much. These are the big three of the web's latest - the new places to hang out.
Join up for free, then spend hours creating a personalised profile complete with wallpaper, or "skins", add your favourite photos, collect "friends" and post "comments" on others' pages.
Post tidbits about yourself, anything from favourite bands and school or workplace, to your biggest fears.
Choose whether only "friends" can see your profile, or if it's available for anyone to read. Instant message ('IM') or "chat" with friends, or complete strangers for that matter.
Bebo is the most popular networking site in New Zealand, according to internet safety group, Netsafe. It has 35 million members worldwide and counting - five people sign up every second, mainly teens. It's believed to have more members here than Myspace, which claimed in February to have 500,000 Kiwi users, and has a slightly older audience.
Facebook, the newest phenomenon, reported 33,000 New Zealand network members as of last month. Begun as an online forum for university graduates, Facebook recently opened its networks to all. Hitwise New Zealand told the Herald on Sunday Kiwi visits to the site were exploding - its market share was up 180 per cent over the past two months.
Visits to Bebo increased 15 per cent in that time.
During the week ending August 4, it had 30 per cent market share, or the number one spot within the net communities and chat section.