“Jews betrayed their own for many reasons: sometimes, as we have seen, for profit; sometimes, out of fear for themselves or someone dear to them; sometimes under cruel torture; and sometimes, for petty revenge. Dana I. Alvi provides an example of the last category.
When the [Warsaw] uprising was crushed, we all went into hiding, anticipating arrival of the Soviet Army. In November, 1944, one of the Jewish women we saved argued with a group of Jews and brough the Germans who then killed 18 people, including her nephew and her elderly sister. […] For us, and the Jews who passed through our home, the greatest fear was that someone from the ghetto would betray [us]. The names of Jewish traitors are a record in history books authored by Jews.”
Poland’s Holocaust: Ethnic Strife, Collaboration with Occupying Forces and Genocide in the Second Republic, 1918-1947, Tadeusz Piotrowski