SAN FRANCISCO — Do you know who can see what you are posting on Facebook, including your photos, birthday and personal cellphone number?
Chances are that you don’t.
And Facebook is worried that you will start sharing less – or maybe even move to more anonymous services – unless it helps better manage your private information. On Thursday, the company announced that it would give a privacy checkup to every one of its 1.28 billion users worldwide.
Facebook, which is based in Menlo Park, Calif., will also change how it treats new users by initially setting their posts to be seen only by friends. Previously, those posts were accessible to anyone.
And it will explain to both current and new users that setting their privacy to “public” means that anyone on the Internet can see their photos and messages.
The change in default settings and the person-by-person review is a sharp reversal for Facebook, whose privacy settings are famously complicated. Some users may be shocked when they see just how widely their personal information has been shared.
For most of its 10-year history, Facebook has pushed and sometimes forced its users to share more information more publicly, drawing fire from customers, regulators and privacy advocates across the globe. That helped make Facebook the world’s largest social network and an advertising behemoth.
But the company recently concluded that its growth depended on customers’ feeling more confident that they were sharing intimate details of their lives with only the right people.
“What we really want is to enable people to share what they want,” Mark Zuckerberg, Facebook’s co-founder and chief executive, said in an interview last month.
And more sharing means more growth and more opportunities to place ads for Facebook.
Zuckerberg has also watched the rapid growth of privacy-friendly services like WhatsApp and Snapchat and anonymous sharing apps like Secret and Whisper, which compete for the time of many Facebook users, especially the younger ones. That prompted him to strike a deal this year to buy WhatsApp for as much as $19 billion and take steps to make the Facebook social network more respectful of user privacy.
“Private communication has always been an important part of the picture, and I think it’s increasingly important,” he said. “Anything we can do that makes people feel more comfortable is really good.”
Nearly 9 in 10 Internet users have taken steps online to remove or mask their digital footprints, according to a telephone survey of 1,002 U.S. adults in July by the Pew Research Center.
Facebook is also feeling enormous pressure from privacy regulators around the world, said Marc Rotenberg, president of the Electronic Privacy Information Center, an advocacy group. “If they don’t make these changes, they’re going to be sanctioned,” he said.