> Anubis uses a proof-of-work challenge to ensure that clients are using a modern browser and are able to calculate SHA-256 checksums
https://anubis.techaro.lol/docs/design/how-anubis-works
This is pretty cool, I have a project or two that might benefit from it.
But I find that when it comes to simple serving of content, human vs. bot is not usually what you’re trying to filter or block on. As long as a given client is not abusing your systems, then why do you care if the client is a human?
Well, that's the rub. The bots are abusing the systems. The bots are accessing the contents at rates thousands of times faster and more often than humans. The bots also have access patterns unlike your expected human audience (downloading gigabytes or terabytes of data multiples times, over and over).
And these bots aren't some being with rights. They're tools unleashed by humans. It's humans abusing the systems. These are anti-abuse measures.
In the interest of bringing the AI bickering to HN: I think one could accurately characterize "block bots just in case they choose to request too much data" as discrimination! Robots of course don't have any rights so it's not wrong, but it certainly might be unwise.
Not when the bots are actively programmed to thwart them by using far-flung IP address carousels, request pacing, spoofed user agents and similar techniques. It's open war these days.
If the abuser is using request pacing to make less request then that's making the abuser less abusive. If you're still complaining that request pacing is not pacing the requests down enough because the pacing is designed to just not bring your server down and instead make you consume money, then you can counteract that just by tuning the rate limiting even further down.
The 10s of thousands distinct IP address is another (and perfectly valid) issue, but it was not the point I answered to.