The Post Office example isn't very good because most mail carriers don't serve more than a few thousand people (maybe a lot less in the 'burbs) so it would be v

The Post Office example isn't very good because most mail carriers don't serve more than a few thousand people (maybe a lot less in the 'burbs) so it would be very hard to get enough money together to make it worthwhile to kill any one individual. But the greater point, that people could act irrationally and cause entirely innocent people to be killed is still a possibility and tough to refute.