Remember the slogan from those old public service announcements, “It’s 10 PM, do you know where your children are?” If that campaign ever gets reinvigorated, a more fitting slogan for the sign of the times should be, “It’s 10 PM, do you know what your children are doing online?”

If a recent study of online teen behavior is any indication, the answer to that question is a resounding NO. According to security company McAfee, most parents don’t actually know the real online behavior of their teens and are essentially having the wool pulled over their eyes by their highly tech-savvy teens. The company’s 2012 Teen Internet Behavior study aggregated data from interviews with more than 2,000 parents and kids (ages 13-17) and found that teens are not only engaging in risky behavior, but are also skillfully hiding it from mom and dad.

With the sheer amount of time kids are spending online, it’s a wonder they’re able to get anything else done. According to the survey, teens in this age group are spending an average of FIVE hours a day online, but parents only think that they’re on the Internet for three. What’s even more shocking is that 10 percent of kids in the poll reported spending more than 10 hours a day online. Yes, ten!

Nearly 90 percent of teens polled use Facebook and post photos, divulge personal information, “stalk” friends and comment on posts, with half admitting to posting “risky” comments online. And Facebook isn’t the only thing they’re doing online. Teens are also pirating music (30 percent), looking up answers to homework (48 percent) and even hacking email accounts (8 percent).

Kids are engaging in these suspicious and surreptitious behaviors online, yet many parents still remain obscured from what their kids are doing. Almost three quarters of parents polled “trust” that their teens are not accessing inappropriate content online, but 43 percent of kids admitted to looking at simulated violence and a third to online pornography.

Parents are trying to stay ahead of their kids’ behaviors by using security measures, implementing parental controls and even using GPS technology to keep track of their kids, but 23 percent of parents are “overwhelmed” by technology and are not monitoring their kids at all. Not sure which is worse, that, or the 22 percent of parents who think their kids can’t get in trouble online (clearly in denial).

Despite parents’ best efforts, more than 70 percent of teens have found methods to bypass this monitoring. McAfee lists the following 10 methods teens are using to keep their online behavior hidden from their parents:

• Clearing the browser history (53%)
• Close/minimize browser when parent walked in (46%)
• Hide or delete IMs or videos (34%)
• Lie or omit details about online activities (23%)
• Use a computer your parents don’t check (23%)
• Use an internet-enabled mobile device (21%)
• Use privacy settings to make certain content viewable only by friends (20%)
• Use private browsing modes (20%)
• Create private email address unknown to parents (15%)
• Create duplicate/fake social network profiles (9%)

So, what’s a parent to do? If your kids aren’t online yet, be thankful. But also, start opening up a dialogue about online safety, just as do with safety in the physical world. If your kids are online, communicate with them about what kinds of things they’re doing online and more importantly, familiarize yourself with the digital world that’s at their fingertips.