They are Jews who not only converted out but then turned on Judaism and Jews in a near rabid attack, misrepresenting Jewish texts to bring about the deaths of Jews and destruction of their culture. More of them here.
Is it only Jews who have the peculiar habit of not only opting out but then turning on their families, their people, their religion, their culture and their national identity to destroy from the roots?
I've blogged about Judah Leib Magnes asking Secretary of State George Marshall and President Truman to halt monetary contributions to the fledgling state of Israel which would virtually assure an Arab military victory (he thought if Israel couldn't fight then the Arabs would stop, too, and make peace). I've blogged about Peter Beinart. And about J Street's Jeremy Ben-Ami, son of the Irgun's Mike.
I am not referring to legitimate criticism of errors and faults and even crimes of individual Jews and the state's apparatus which need be highlighted and corrected but to a certain strain an antipathy which rejects or leads to the fundamental undermining of Zionism in the activities of persons and groups.
The dangers that were launched against Jews centuries ago by turncoats are perhaps different but the theme is still the same: 'we're not just leaving but we are coming back to get you'.
In that scenario, Israel, Zionism and Judaism need defend themselves.