Umm... I was going to say something to the effect of how it isn&#x27;t technically an instance of the halting problem to detect penises in Minecraft, but it&#x27;s pretty close in the face of a hostile adversary.<p>Then I remembered that with redstone, to say nothing of command blocks, it really is close to the halting problem. Maybe not quite technically, since the detection program would be running in a context with significantly more resources (halting problem in the strict sense applies to Turing Machines with infinite resources), but it&#x27;s still close enough to cause you a lot of practical problems, enough to say that it&#x27;s probably an instance in practice even if not in theory.