Comment by tptacek
16 hours ago
It's weird to believe data center based, Internet-scale scraping operations will be less able to allocate compute to proof-of-work challenges than individual users. This is design problem with things like Anubis: proof-of-work depends on a cost asymmetry between attacker and defender. But in scraping, both legitimate users and scrapers get the same value out of a transaction.
And yet, in practice, it's true. I was getting about 600K requests to my Forgejo server a day from crawlers making idiotic queries: https://honeypot.net/2025/12/22/i-read-yann-espositos-blog.h...
I just checked, and these many months later after installing Anubis, I'm getting about 14K requests per day. It's unreasonably effective at cutting crawler abuse. It should not be able to reduce my traffic by 98%, and yet in practice that's exactly what it's doing.
I think that the most abusive scrapers are operated by people who absolutely suck at programming. If they didn't, they wouldn't be crawling every permutation of "show me the git blame for every file in this repo for every commit in its history". Were they actually competent, they'd be investing in smarts such that they weren't crawling a web frontend to get that information.
Have you compared against adding a JavaScript requirement with no proof of work?
Yes. That helped, but not nearly so much.
For PoW to work, you don't need scrapers to have less compute than users, you only need their compute advantage to be less than the load-generation advantage they would otherwise have. And unlike legitimate users, scrapers aren't carefully picking the URLs they request, so the average value they get out of it is probably rather low. They have to make it up in volume.