How is cheating possible?

[tinkthank]

This is sad.
Since I had no idea that there was a cheat at all (I had to search with "Norfleet" in the subject title to find that thread, and just read it, boy is it long), I had never really thought it possible. I am not personally worried since I don't play competetively nor with people I could ever imagine even wanting to cheat, but I still think that measures should be undertaken to ensure that "hacks" or whatever you call them are as difficult to do as possible. I have no idea about computers or hacking, but I imagine that nothing is completely safe.
In any case, I think the original question is a good one, and if it won't be answered here, it should at least be not-answered by means of an assurance that smart people are working on a cheat protection.