In article , BAC
writes

Cars, buses, taxes, trains, and trams are all different, and are customarily
used to meet different needs, but they are all passenger vehicles - even
when they are not actually carrying passengers. Similarly, poisons intended
to kill organisms for pest control purposes are all pesticides, even though
the nature of the pests may be very different. And, fortunately, it is not
mandatory to use a pesticide just because one encounters a 'pest' :-)

Does that mean that a spam filter is a pesticide?
--
Alan & Joan Gould - North Lincs.