I'm curious if the PoW component is really necessary, AIUI untargeted crawlers are usually curl wrappers which don't run Javascript, so requiring even a trivial amount of JS would defeat them. Unless AI companies are so flush with cash that they can afford to just use headless Chrome for everything, efficiency be damned.
Sadly, in testing the proof of work is needed. The scrapers run JS because if you don't run JS the modern web is broken. Anubis is tactically designed to make them use modern versions of Firefox/Chrome at least.
They really do use headless chrome for everything. My testing has shown a lot of them are on Digital Ocean. I have a list of IP addresses in case someone from there is reading this and can have a come to jesus conversation with those AI companies.
