FACEBOOK is the antithesis of privacy. The user agrees...upfront...the data uploaded can be used by anyone for anything. On the other hand...if the user harbors some qualms about such revelation or use...then...they're directed: do not upload.
However...almost all users expect plenty of "looking"...and...as the U.S. Supreme Court in US. v. KATZ pointed out, "Anything a person chooses to reveal to the public is in the public domain and a right to privacy with respect thereto can't be demanded."
FACEBOOK went further and compelled the user in exchange for the platform...the user agreed not to bark or make noise about who looked or who used...and...always had the choice to "keep private" if the user chose such closet. As FACEBOOK-Zuckerberg noted, "Secrecy molts no feather".