@corbet @LWN I'm wondering if a link that a human wouldn't click on but an AI wouldn't know any better than to follow could be used in nginx configuration to serve AI robots differently from humans, in a configuration that excluded search crawlers from that configuration. What such a link would look like would be different on different sites. That would require thought from every site, but also that would create diversity which would make it harder to guard against on the scraper side, so possibly could be more effective.
I might be an outlier here for my feelings on whether training genai such as LLMs from publicly-posted information is OK. It felt weird decades ago when I was asked for permission to put content I posted to usenet onto a CD (why would I care whether the bits were carried to the final reader on a phone line someone paid for or a CD someone paid for?) so it's not inconsistent in my view that I would personally feel that it's OK to use what I post publicly to train genai. (I respect that others feel differently here.)
That said, I'm beyond livid at being the target of a DDoS, and other AI engines might end up being collateral damage as I try to protect my site for use by real people.