The issue of cyber-bullying has made headlines recently following the suicides of teens who reported being harassed online, but another type of online behavior also may worry parents: Some websites collect teens' online habits, then sell the information to advertisers who may target the children for products and services.
A recent Wall Street Journal investigation found that children were more likely to be tracked than adults were.
"There's no rules out there," Laura Blaire, a concerned mother, told ABC News.
The practice also bothers James Steyer, the CEO and founder of Common Sense Media, a nonprofit group that provides advocacy and education for parents and children regarding media issues.
"What if my daughter has a concern about her body image and has an issue with eating disorders or a potential eating disorder, and she is suddenly targeted with weight loss drugs?," Steyer asked. "I think that it is a very, very frightening thing in many ways as a parent and as an educator.
"Parents simply don't understand how sophisticated the technology is and how much that sophisticated technology can be used to track and then target your kids with ads and other messages that simply are not appropriate," he said.
Steyer is a proponent of a list that would restrict online marketers similar to the "Do Not Call" list that currently limits telemarketers.
Click HERE for tips about protecting your children's privacy online.
The Federal Trade Commission is considering a proposal that would make it illegal for companies to trade in private information about young people who don't consent to online tracking by marketers.
The proposal , along with the suggestion for an online "do not track" list, will be part of an upcoming report.
That may be welcome news to many parents.
A Zogby International poll released today found that 92 percent of parents fear that their children were sharing too much information on line, and that 85 percent of parents were more concerned about online privacy than they were five years ago.
It also found that 91 percent of parents think search engines and social networking sites should not be able to share kids' physical location with other companies until parents give authorization.
"I don't want people knowing where I live, it creeps me out," Randy Shapiro, 14, said.
Jon Leibowitz, the chairman of the FTC, told ABC News that the agency has brought cases against companies that use unfair or deceptive practices to collect information online.
Common Sense has launched a comprehensive campaign to help families protect their children's personal information and online reputations. Dubbed "Protect Our Privacy -- Protect Our Kids," the campaign will include information, advocacy and awareness, consumer tips and educational materials for schools and teachers around the country.
Zogby surveyed 2,100 parents and 401 teens between the ages of 15 and 18. The poll was conducted between Aug. 13 and 20.