Most U.S. tweens, 10- to 12-year-olds, have at least one social media account and many go online without any supervision from their parents, according to a survey released on Tuesday.
Facebook is the most popular platform among tweens. Although the site says users must be at least 13 years old to log on, 85 percent of tweens said they have an account and a similar number admit they use it every day.
"Younger and younger kids are going out there really unsupervised," said Michelle Dennedy of the online security company McAfee, which commissioned the poll of 1,173 young people aged 10 to 23 years old and 1,301 parents.
The threats to children of unsupervised use of the Internet are well known and range from identity theft, cyberbullying and sharing photos and videos to pornography and sexual predators.
But despite the dangers, 82 percent of preteens say they think social media sites are very safe, or somewhat safe, and 79 percent of parents agree.
Nearly half of youngsters also report sharing personal information online such as their email address, and 28 percent have revealed the school they attend.
Many parents are also unaware of the time their children spend online. The poll showed 52 percent of youngsters spending five or more hours a day online but most parents think they spend only one to two hours.
Dennedy said many parents are overwhelmed by the onslaught of technology available to their children and feel like they can't keep up with their tech-savvy children.
More than 80 percent of the parents of preteens say they don't have the time or energy to keep up with everything their children do online. Only 9 percent say they know how to find out what their children are doing online.
Children are also skilled in hiding their online activity from their parents. More than half of tweens, 58 percent, say they know how to keep their online use a secret and a quarter admitted they had cleared or hidden what they have done online.
"There's a lot of positive stuff out there, and what we have to do as adults is really separate the good from the bad," Dennedy said.
She suggested parents have regular conversations with their children about using the Internet and that they educate themselves about online safety.
Although 71 percent of parents questioned in the poll said they had talked to their children about online behavior, only 44 percent of children agreed that they had.
"It's still the Wild West out there and because they are digital natives, our youth are engaging in all kinds of unsafe behavior without the benefit of how their actions will affect their lives," said Dennedy.
Other popular sites for teens, tweens and college-age youths include Twitter, Instagram, Pinterest and Tumblr, the survey found.
It was conducted from April 3 to 15 and has a margin of error of plus or minus 2 percentage points.