Before I start telling you the story which led me to write on this topic, I feel I'm obligated to reveal the main idea of this post:
In order to copy programming homework, you mustn't be a dumb fuck. (And a few ways to avoid being one)
And now the story. I have a colleague (let's call him John) at work who also checks programming courses homework at my college. Our college is really harsh about students copying programming homework (you can xerox algorithms homework, but programming is a big no-no).