"Broadly speaking, Jews who hate Israel fall into three categories: a) the famous, of which Noam Chomsky is about the only one; b) the well-known, like Norman Finkelstein and Tony Judt, and c) others who are not known beyond their immediate circles but who do lurk in various crevices of the Internet. Altogether, as I will explain below, it is not likely that there are more than a few thousand of these haters active worldwide, say fewer than 10,000 and probably no more than half that number. Considering that there are more than 13 million Jews in the world at the moment, the proportion of those who actively hate Israel, about 0.04 of one percent, might well be considered to be modest indeed. "In Canada, we have one or two in the locally "well-known" category, such as non-credible players like Naomi Klein and her husband, what's-his-name, and Judy Rebick.
For more about this very interesting look at a sad phenomenon, read Professor Cohn's entire piece here.