The idea is to discourage botnets by increasing the cost of building a botnet. It is about as good of an idea as you're going to find. Of course there would be

The idea is to discourage botnets by increasing the cost of building a botnet. It is about as good of an idea as you're going to find. Of course there would be other ways but this is more effective than captchas, and lets you decide how important it is to you to prove that you are a human or how important it is to you that you are only dealing with humans. You could make a system like this based on IRL contacts but that would potentially compromise your privacy even more. It's also easier to exploit in some ways than a simple payment.