The day Angela Thomas intercepted a sexually-charged instant message sent to her then-13-year-old daughter, she made a drastic decision.

Thomas, a Tennessee author and the single mother of four children, pulled the plug on her children's cyber lives.

"That was it for me," she said.

She eventually learned that the message her daughter received came from a stranger. "I realized that things can happen in a moment that I have spent years trying to protect them from," she said.

Thomas has written a book, "My Single Mom Life: Stories & Practical Lessons for Your Journey," about being a single parent. Her admission about her children's unplugged lives is just one chapter of the book, but an essential one as far as she is concerned.

"I think they have the rest of their lives to navigate inappropriate information," she says of her kids, ages 9, 11, 13 and 17.

After the instant messaging incident, Thomas made a household rule - no more Internet, no more instant messaging, no MySpace pages. That was four years ago, and the rule still applies.

Thomas has Internet access only on one laptop computer. If her children need to use the Internet for school research, she assists them. The older kids can use the Internet for school research as long as Thomas is nearby.

From the start, Thomas said she was surprised by how supportive other parents have been. "I think that more parents wish they had gone ahead and drawn those strong boundaries a long time ago," she said. "I cannot even count how many women have said, 'I have already allowed this. … How do I go back?'"

Although Thomas said she realizes there are good filters for computers, she isn't confident that they do enough. And as a single parent, she doesn't have the time to properly oversee what her children are sending and what they are receiving. "It's just too much at the end of the day to monitor," she says. Thomas believes parents may not realize just what is being implied and written on MySpace pages, maybe not by their children but by anonymous visitors to the sites.

"I have read the MySpace pages of their (her children's) friends," she said. "The language is so vulgar … the innuendo. I wouldn't let my kid watch a movie with that language."

For the most part, Thomas says her children don't rebel against the rule. Her son didn't even realize there was a rule. And there are times when Thomas believes her children actually get comfort from the restrictions.

"I think it is a little bit of relief … 'My mom says no,'" she said. "I've given them the out to blame me."