Check this hilarious, and very interesting, video:
This short video is just about the perfect illustration of kind of sicko paranoia rabbinical "Judaism" fosters in its ranks. First, the gut wrenching fear of some anti-Semite coming to kill them all. Second, the putative anti-Semite is seen as screaming "Allahu Akbar" (hint, hint). Then the typically convoluted Talmudic logic in allowing guns to be carrying on the Sabbath. But most amazing of all is the obvious buffoonery of the kind of "training" this rabbi delivers (turns out that the Revolver Rabbi - Moscowitz - had been fired from the NYPD in the early 1990s)
In reality, of course, the security of synagogues is typically trusted to ad-hoc defense groups, often under the "Betar" label, which, rather than training people on how to hide behind plastic tables from bullets, do such things as occupy all the parking spaces around a synagogue to prevent a possible car bomb from getting too close. These groups are typically kept informed of possible security risks by the local Israeli representation which, in turn, can rely on them as auxiliaries.
No, the kind of stuff you see on this video serves one purpose only: to terrify the "trainees" into a "us versus them - we are on our own" kind of paranoia which will make them circle the wagons and not question their leaders. Think of it as the rabbinical version of the "color coded alert levels" of the Bush administration: utterly useless, but quite scary nonetheless.
It is all too often forgetten that many, I would say most, Jews are the first victims of the ugly system of control which their leaders (religious or secular) have held over them for centuries and which is still present today. Sure, rabbis nowadays cannot sentence somebody to death or have him/her flogged as they could in the Jewish shtetls in Europe before the second half of the 19th century. But while their methods have changed, their goals have not.