re: But what if there's only a one-in-a-million chance...
Indeed - stretching the rather poor analogy even further
What you would want to do is conduct a study to find out IF someone is making a doomsday device.
What we need is good funding for ground based and perhaps IR based orbital surveying programs to find and track these things. THEN we find out if there's a doomsday rock out there getting ready to attack.
What we don't need is panic merchants like EP telling lies