Facebook made some private posts public for as many as 14M

Facebook says a software bug made some private posts public for as many as 14 million users over several days in May

Facebook said Thursday that it would notify 14 million users that posts they meant to share privately may have been published publicly, the company's latest setback as it tries to rebuild user trust after the Cambridge Analytica scandal.

Facebook said this privacy setting bug affected users posting between May 18 and May 27. The software flaw was apparently live for 10 days last month and the company didn't give users any kind of warning. But Facebook accidentally set "public" as the default for posts, too. Typically, the social network assigns new posts the same privacy setting as the user's most recent post, unless otherwise instructed.

"We recently found a bug that automatically suggested posting publicly when some people were creating their Facebook posts", said Erin Egan, Facebook's chief privacy officer, told CNN. And while the bug was only in effect for a few days, it's an example of how many different settings users have to be aware of on Facebook.

A Facebook post's privacy settings, with a checkmark next to the users' chosen default setting.

"It will take some time to work through all the changes we need to make across the company", Zuckerberg said on the first day of hearings.

The blunder is yet another embarrassing gaffe for Facebook at a time when the biz can hardly afford to cast further doubt on its ability to secure the personal details of its users. Facebook will soon start individually informing the people who were affected by the bug.

Matt Navarra, who describes himself as a social and digital media consultant, tweeted a screen grab of the alert to users.

Facebook data - do we get what we deserve? That means if an eagle-eyed user didn't catch the bug, they likely shared some status updates publicly on Facebook that they meant to share only with friends.

One of Facebook's key privacy features is that it lets people decide an audience for their posts.

Users can also manually change the privacy of the posts - anywhere from "public" to "only me" - when publishing to Facebook.