Facebook’s shadowbanning patented document now uploaded proves its officially true

For example, the social networking system may receive a list of proscribed content and block comments containing the proscribed content by reducing the distribution of those comments to other viewing users. However, the social networking system may display the blocked content to the commenting user such that the commenting user is not made aware that his or her comment was blocked, thereby providing fewer incentives to the commenting user to spam the page or attempt to circumvent the social networking system filters. 

patft.uspto.gov/netacgi/nph-Parser?Sect2=PTO1&Sect2=HITOFF&p=1&u=/netahtml/PTO/search-bool.html&r=1&f=G&l=50&d=PALL&RefSrch=yes&Query=PN/10356024

Just in case you wanted proof they did it.

AC