[Loic]

Proof of work, even "custom", where the user does not need a particular interaction with the page, does not work. The scrapers are running headless Chrome and solving the work. They do not care, they do not pay the bill, the compromised system's owner pays the bill.

I have such system for the registration form on one of my website to prevent the double validation of emails to be used to spam emails of victims. The PoW challenge prevents less than 10% of the bots.

[ArtTimeInvestor]

Thats why I said proof of work that is used to mine a cryptocurrency to pay the bills of websites that serve information.

As long as the website gets paid more than the cost of serving the pages, it does not matter if a human or a bot did the POW.

Securing signup forms is another issue. Maybe related. But not what I was referring to.

[Loic]

Very good point, I missed the point that the PoW is paying the publisher. I will have to dig into this, this is a pretty nice idea.

[inigyou]

Residential proxy users don't get to run computation on the proxies.