It’s not been a great year for Facebook.
Earlier this year, the site hit the headlines after it was discovered that it had shared personal data of some users with Cambridge Analytica .
Now, Facebook has revealed that a software bug changed 14 million users’ default privacy settings to public.
Erin Egan, head of privacy at Facebook, said: “We’d like to apologise for this mistake.
"We recently found a bug that automatically suggested posting publicly when some people were creating their Facebook posts.
"We have fixed this issue and starting today we are letting everyone affected know and asking them to review any posts they made during that time.
"To be clear, this bug did not impact anything people had posted before - and they could still choose their audience just as they always have. We’d like to apologise for this mistake.”
According to Facebook, the bug was active from 18-22 May, and has since been fixed.
The issue meant that when users posted on Facebook, their post automatically went ‘public’ - meaning anyone could see it.
If you were one of the 14 million users affected, Facebook will notify you, and show you a graph revealing if any of your posts went public.