These sites need to access to 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.
Toś te sedła trjebaju pśistup k wašej identiśe Facebook (abo muse wěźeś, chto sćo), aby funkcioněrowali. To teke groni, až Facebook móžo wšymu slědowaś, což na toś tych sedłach cyniśo.