Smokey, you asked a valid, disturbing question. Pinto, the hatred seems to have moved away from individual Jews to Israel. Those who object to Israel's treatment of the Palestinian are NOT automatically anti-Semitic. Those who object to Israel's right to exist where it is located, even though the United Nations voted to establish it, are, in my view, guilty of anti-Semitism. There are plenty of those folks among the radical elements in the Middle East and, sadly, among Americans who support them.
Furthermore, there are vicious anti-Semites among the radical right militia members in the US, who harbor hatred for all Jews. For radicals, whether pro- or anti-Islam, attacking audience members in New York at a show especially oriented towards Jewish people would be a triple coup -- a highly visible target (a Broadway theater) in the United States, where the attack is likely to kill lots of Jews and those who, while not Jewish, are friendly towards Judaism and Jewish people.
The cursory bag checks at theater entrances, if I'm not mistaken, started around the time when theaters started selling snacks. The checks seem more designed to find food than weapons.
We're living in an era where we call must learn to live with metal detectors and X-ray devices. Are they necessary at Fiddler? I hope not, but guessing wrong could have tragic consequences.
Audrey, the Phantom Phanatic, who nonetheless would rather be Jean Valjean, who knew how to make lemonade out of lemons.