This was not something that was previously known on a wider basis, meaning many people, especially newer users, were inadvertently sharing their posts with everyone.
“We want to do all we can to put power and control in people’s hands,” said Facebook’s announcement.
“This new tool is designed to help people make sure they are sharing with just the audience they want. Everything about how privacy works on Facebook remains the same.
We always advise people that are conscious of their privacy to regularly check their profile settings on Facebook so you know exactly who is seeing what on your Facebook.