These sites need to access your Facebook identity (or know who you are) in order to work. This also means that Facebook can track everything you do on these sites.
Tute sydła trjebaja přistup k wašej identiće Facebook (abo dyrbja wědźeć, štó sće), zo bychu fungowali. To tež rěka, zo Facebook móže wšemu slědować, štož na tutych sydłach činiće.