Children using Club Penguin and other kid-oriented websites are finding ingenious ways to subvert privacy settings to reveal personal information, says a mom who has gone undercover and blogged about her experiences.

Sharon Duke Estroff, a parenting columnist and blogger based in Atlanta, Ga., said she "spied" on her children, ostensibly to better understand their problems when they came up.

"I want to see what's really going on," Duke Estroff said recently in an interview with Nora Young on the CBC Radio technology show Spark. "It helps me formulate a plan for parenting — what to talk to my children about.

"It's not that I'm trying to spy on my kids. I do feel they need privacy but I also don't think they need complete privacy, especially in elementary school."

Duke Estroff, who has four young children, said she, like many parents, is comforted knowing there are strict privacy settings on kid-oriented websites such as Club Penguin and Barbie Girls to prevent youngsters from sharing personal information, even when they want to.

For example, many of these websites prevent kids from using proper nouns and numbers, so that names, ages, phone numbers and addresses cannot be shared easily.

But to Duke Estroff's surprise, kids found ways around those restrictions.

"For example, I did some undercover work at Barbie Girls, and there was a conversation where a girl was saying, 'How old are you?' And the other child was saying, 'I'm won and too. And she said, 'Get it?'

"And the other child said, 'I'm one less than that' and another child said,'I'm mine,' because she can't say nine so she said 'mine', with an m. So they'll get around it.

"Another pretty common way is they'll count things. So they'll say, 'how many dots are you,' and they'll put in nine dots. They're pretty adept at it."

Mostly, the information shared is harmless, but it can lead to problems, she said.

For instance, to prevent online bullying and negativity many of the websites also try to block out certain phrases.

"Kids will rearrange words and the cyber bullying will get through," Duke Estroff said. "So for example on Club Penguin, you can't say 'I don't like you' in one stream. However what the kids do is they break it up into separate (word) bubbles, and in total it will come out as a series of four bubbles," she said.

Some girls also share passwords will their latest best friends.

"But unfortunately, friendships at that age change," Duke Estroff said. "They're so fluid. Your best friend for this week may not be your best friend next week. And you happen to have their password, conveniently, so you can do some damage.

"So they'll get one another in trouble. What happens in school will carry over. So let's say there's a score to be settled on the playground. They could go on (the website) and they can pretend they're another child and walk up to another child and say 'I think you're hot' or 'I have a crush on you' and sort of embarrass that child."

What this shows is that companies can only do so much to prevent children from giving out personal information. Some websites even have tried blocking any words that were misspelled.

"It almost becomes sport for the kids, trying to work around (these filters)," Duke Estroff said. "Part of the fun for them is to see if you can get around these filters."