San Francisco - Facebook is now allowing teenagers to share their posts on the social network with anyone on the internet, raising the risks of minors leaving a digital trail that could lead to trouble.The change announced on Wednesday affects Facebook users who list their ages as being from 13 to 17.Until now, Facebook users falling within that age group had been limited to sharing information and photos only with their own friends or friends of those friends.The new policy will give teens the choice of switching their settings so their posts can be accessible to the general public. That option already has been available to adults, including users who are 18 or 19.As a protective measure, Facebook will warn minors opting to be more open that they are exposing themselves to a broader audience. The warning will repeat on every post, as long as the settings remain on "public".Relaxed standardsThe initial privacy settings of teens under 18 will automatically be programmed so posts are seen only by friends. That's slightly more restrictive than the previous automatic setting that allowed teens to distribute their posts to friends of their friends in the network.In a blog post, Facebook said it decided to revise its privacy rules to make its service more enjoyable for teens and provide them with a more powerful megaphone when they believe they have an important point to make or a cause to support."Teens are among the savviest people using social media, and whether it comes to civic engagement, activism, or their thoughts on a new movie, they want to be heard," Facebook wrote.The relaxed standards also may help teens spend more time on Facebook instead of other services, such as Snapchat, that are becoming more popular hangouts among younger people. Facebook CEO Mark Zuckerberg, though, says that the company's internal data shows its social network remains a magnet for teens.Giving people more reasons to habitually visit its social network is important to Facebook because a larger audience helps sell more of the ads that generate most of the Menlo Park, California, company's revenue.Facebook hasn't disclosed how many of its nearly 1.2 billon users are teens.The teen audience is large enough to give Facebook periodic headaches. As its social network has steadily expanded, Facebook has had to combat sexual predators and bullies who prey upon children on its service.Facebook doesn't allow children under 13 to set up accounts on its service, but doesn't have a reliable way to verify users' ages.