This is where I always draw the distinction between the internet and the www. The scripts I consider malicious are for the most part delivered from the internet. The Google index is not part of the internet. What Google attempts to do instead is to use filters of various kinds to stop these malcious scripts from entering the Index.
Most of these scripts are clever and often blow by the Google filters and are indexed rather rapidly. Google does eventually catch up, but by then a new script is developed and the hole process repeats itself.
This my friends is indeed part of the problem. This is why you see sites go up over night. I agree this is how some cheaters operate. Get aquainted with the internet and it all makes sense. greek39