The shabbat book snatcher
A couple of men went to an Orthodox synagogue in London for a friend's son's barmitzvah. They both brought some reading matter for any longueurs during the service.
After one of them was called up to the Torah, he returned to his seat to find his book missing. The other guest's book also went awol, too.
When their friend later discussed the vanished volumes with a synagogue officer, he was told that books disapproved of were liable to removal.
One of the books was written by Martin Buber, the other by the Chief Rabbi.