Back to the "Are IPM's worth it?" question.
I say no, however during war they are fun to annoy people with
However, sometimes, if your attacking someone and the sim says your deathstar blows up they can be good to save that deathstar and make a profitable attack.
IPMs can hit moons

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IPMs are destroyed after one attack.
You have to send espionage probes to see what you have destroyed.
IPMs don't create a DF.
