Errata

As stated, the Deadly Probes Hypothesis postulates Von Neuman probes that:

i) detect EM radiation from planets, and
ii) destroy such planets.

However, there is a serious logical flaw here. Should a civilization construct a
network of such probes, why would the probes wait for EM radiation?

Given the existence of such probes, it would be trivial to detect earlier stages of a
civilization's development by sending probes to each potential solar system or
planet, and watching for the development of intelligent species (e.g. buildings,
cities, lights, satellites, etc.) - or even life itself - from close up. (Since we
are assuming von Neuman probes, this is simple to do since they are self-
replicating.)

(If a civilization were cautious / paranoid enough, they could even monitor planets
remotely, and launch destructive countermeasures as soon as life-indicating
ingredients were detected in an atmosphere.)

Waiting until EM radiation has been sent out would be unnecessarily risky - how could
one know that a new civilization hadn't developed fast enough to already be in space
by the time countermeasures were taken, or indeed was paranoid enough to operate in
stealth mode from day one