For a few days last month, a software bug caused 14 million Facebook users' default setting for sharing content to be "public", meaning that some of their posts meant to be kept private were accessible to anyone on the internet, the company said Thursday.
But, according to Facebook, the bug automatically suggested that users make new posts "public", even if they had previously restricted to "friends only" or another private setting. The tool usually remains on the setting that was used most recently so that a user who only wants to share posts with friends does not have to keep selecting that option.
The bug affected as many as 14 million people, the company said.
The problem did not change who could see older posts, Facebook chief privacy officer Erin Egan said in a statement.
It will also display more detailed information about the bug, which Facebook has referred to as a 'technical error'.
The bug affected posts shared between May 18 and May 27, though Facebook started rolling out a fix on May 22.
A message will prompt them to "Please Review Your Posts", while a link will direct the user to view a list of what they shared during the 10 days that the bug was active.
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. "We'd like to apologize for this mistake". It's admitting the mistake itself, doing so promptly, and proactively notifying anyone who is affected. Facebook is now in the process of rolling out new privacy menus to all of its 2 billion users.
This week, it has been answering questions about the nature of data-sharing deals with handset makers including Chinese manufacturers Huawei and ZTE. That way, users can reset a post that was inadvertently set to public back to being shared just with friends if they would like.
Affected Facebook users received a notification on the app or website starting Thursday.