They pretty much do their own policing, at this point

They aim for this. The modern state of affairs where they are mostly not permitted to be a law unto themselves is historically the more abnormal one. People know and worry about sharia but are mostly ignorant of talmudic tendencies:

Since the time of the late Roman Empire, Jewish communities had considerable legal powers over their members. Not only powers which arise through voluntary mobilization of social pressure (for example refusal to have any dealing whatsoever with an excommunicated Jew or even to bury his body), but a power of naked coercion: to flog, to imprison, to expel - all this could be inflicted quite legally on an individual Jew by the rabbinical courts for all kinds of offenses. In many countries - Spain and Poland are notable examples - even capital punishment could be and was inflicted, sometimes using particularly cruel methods such as flogging to death.

This was the most important social fact of Jewish existence before the advent of the modern state: observance of the religious laws of Judaism, as well as their inculcation through education, were enforced on Jews by physical coercion, from which one could only escape by conversion to the religion of the majority, amounting in the circumstances to a total social break and for that reason very impracticable, except during a religious crisis.

-Israel Shahak, 'Jewish History, Jewish Religion'