Passover starts tonight and to mark the occasion the Lubavitcher Mitzvah Tanks were out again on the streets of Manhattan. I encountered them as they proceeded down Houston Street in a noisy caravan of rented recreational vehicles emblazoned with the image of Menachem Mendel Schneerson, the seventh rebbe, and their promising slogan of ‘A mitzvah on the spot for people on the go.’ To avoid the prohibition on proselytizing the Lubavitchers are first supposed to ask passersby whether they are Jewish — they are on the look out for the lapsed, idle, or wayward rather than the unchosen — before making their spiel but, personally, I would have happily dissembled in order to get a good deed done in the vicinity. But it was not to be: this was deemed goyim territory, I guess, because the caravan rolled on without stopping.