“We’d like to apologise for this mistake. 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," Egan added.
What exactly happened?
When you post anything on Facebook, there is an option that lets you choose who sees what you are posting. The options include Public, Friends of Friends, Friends and Only Me. While other options limit the audience, “Public” will be visible to everyone who visits your profile.
Facebook remembers your preferred setting and it automatically selects it for the subsequent posts that you share on the platform.
Between May 18 and 22, the bug, however, made every post to “public” even if you had chosen one of the private options. If you did not notice and manually changed the setting to what you had previously set, it is possible that whatever you had posted during May 18 to 22 time bracket -- that was not meant to be “Public” -- was seen by a wider audience.
If you are one of the affected users, Facebook will notify you. In the meantime, your privacy setting has been changed to whatever you had set it to previously. It is still advisable to go and recheck your privacy settings on the platform.