To be able to legally upload photos to Facebook, we need to have the author’s permission.
If we post a personal photo on Facebook and set our profile to “Friends”, we agree to grant Facebook a non-exclusive, transferable, sublicensing, free license all over the world for Facebook to use the photo about our Facebook activity while we have Facebook. If the photo has been shared with other Facebook users and they have not deleted it, Facebook’s photo usage authorization remains valid even after I deleted my account.
However, if we post a personal photo on Facebook and set the “Public” profile, we agree to allow anyone, including Facebook non-members, to access and use the photo and associate it with us (including name and profile).
Practically, by setting the “Public” profile on our Facebook page, we lose the right to prohibit third parties from using the photos we post.