Just last Friday Facebook disclosed a bug has been exposing photo that was uploaded on the social network
personally we know friends that are very sensitive about privacy to the points that family privacy such as photo means alot to them
To this , a Bug with FB Photo API has granted a 3rd party app access to your photo which it shouldn't have under normal circumstances.
In this case , the permission may allow them to share photo in Facebook marketplace or Stories
It is reportedly impacting 6.8 million people , up to 1,500 Apps from more than 800 Developers
To Find out More if you are affected , simply go to https://facebook.com/help/200632800873098?ref=photonotice
and read the instruction shared