how do you want to proof of humanity, without proof of work. that's how psychopaths "work-around".
keep the basics, on which you build.
Discussion
Bots work much more than humans. Proof of work doesn't work against bots.
Aren't we conflating bots with Spam. For spam to be effective, it needs to be easy to pull off on a large scale. Doesn't pow raise the bar which makes spam less effective.
