SAN FRANCISCO — Parents take note: Your teens can now post status updates and photos on Facebook for anyone to see.
The giant social network on Wednesday lifted restrictions on kids ages 13 to 17 that kept them from sharing information with people they do not know. Until now, teens' posts on Facebook could be viewed only by friends and the friends of their friends.
The move presents a tough new challenge to parents trying to keep their kids safe on social media.
"Teens," the company said in a blog post, "want to be heard."
Facebook is ubiquitous among teens. Some 94% of teens are said to have Facebook accounts.
But in a threat to Facebook's status as the world's most popular social network, teens have begun spending more time hanging out on other social networks such as Twitter, Snapchat and Facebook's own photo-sharing service, Instagram.
On these services that they view as being younger and hipper, teens can say whatever they want, and they are less likely to run into their parents.
Critics say loosening privacy restrictions on Facebook puts teens at risk.
As part of the changes, teens now can also let people "follow" them on Facebook and see posts that are made public, similar to Twitter.
Jeffrey Chester, executive director of the Center for Digital Democracy, called on federal regulators to step in and protect teen privacy.
"To parents and teens, Facebook is claiming they are giving them more options to protect their privacy. But in reality, they are making a teen's information more accessible, now that they have the option to post publicly," Chester said. "Today's announcement actually removes a safeguard that teens currently have."
Parents were also alarmed by the changes.
According to a 2012 study from Pew Research, 59% of parents of teens who use social networking sites have talked to their kids because they were concerned about something posted on their profile or account.
Jennifer Tyree, a Peoria, Ariz., freelance writer and mother, said parents should be responsible for regularly monitoring their kids' accounts on Facebook.
"But Facebook shouldn't allow the posts to be public," Tyree said. "There are too many predators out there."
Casey Mullins, a mother of two from Indianapolis, called the changes to privacy for teens on Facebook a "huge risk." Teens, she said, are too young, vulnerable and impulsive to exercise sound judgment about what should be shared publicly.
When she was a teen, Mullins said, she and her friends passed notes in class. Now, she said, those notes are becoming public, significantly increasing safety risks for teens.
"That is just so much responsibility to give teens," she said. "Just as adults have fallen on their face publicly, I think a lot of teens are going to fall on their face publicly. It's going to be very hard for parents and for teens to deal with."
Facebook says it's taking precautions. When teens join the service, their privacy settings will be automatically set to share information only with friends. Teens who choose to change their settings will be asked twice with a pop-up notification whether they are sure they want to share information broadly, Facebook said.
Jim Steyer, founder and chief executive of Common Sense Media, warned that Facebook will use teens' public content for targeted advertising.
"This pop-up notification before making a post public may also be seen as a ploy that somehow implies these teens are giving Facebook the green light to mine their content, and that is entirely unacceptable," Steyer said.
Privacy groups recently sent a letter to the Federal Trade Commission asking it to examine the data Facebook collects on teens.
"As marketers stealthily mine social media data, they will capture a teen's public posts. That data will help create more robust data profiles of teens to be used for targeting," Chester said.
Research from the Pew Research Center has found that although teens are sharing more information about themselves on social media than they have in the past, they are taking steps to protect their privacy.
Youths ages 12 to 17 prefer to manage their privacy settings themselves, but most — 71% — have sought help from friends or parents.