"Non-consensually", as if you had to ask for permission to perform a GET request to an open HTTP server.
Yes, I know about weev. That was a travesty.
robots.txt is a polite request to please not scrape these pages because it's probably not going to be productive. It was never meant to be a binding agreement, otherwise there would be a stricter protocol around it.
It's kind of like leaving a note for the deliveryman saying please don't leave packages on the porch. It's fine for low stakes situations, but if package security is of utmost importance to you, you should arrange to get it certified or to pick it up at the delivery center. Likewise if enforcing a rule of no scraping is of utmost importance you need to require an API token or some other form of authentication before you serve the pages.
"Taking" versus "giving" is neither here nor there for this discussion. The question is are you expressing a preference on etiquette versus a hard rule that must be followed. I personally believe robots.txt is the former, and I say that as someone who serves more pages than they scrape
So what's the solution? How do I host a website that welcomes human visitors, but rejects all scrapers?
There is no mechanism! The best I can do is a cat-and-mouse arms race where I try to detect the traffic I don't want, and block it, while the people generating the traffic keep getting more sophisticated about hiding from my detection.
No, putting up a paywall is not a reasonable response to this.
> The question is are you expressing a preference on etiquette versus a hard rule that must be followed.
Well, there really aren't any hard rules that must be followed, because there are no enforcement mechanisms outside of going nuclear (requiring login). Everything is etiquette. And I agree that robots.txt is also etiquette, and it is super messed up that we tolerate "AI" companies stomping all over that etiquette.
Do we maybe want laws that say everyone must respect robots.txt? Maybe? But then people will just move their scrapers to a jurisdiction without those laws. And I'm sure someone could make the argument that robots.txt doesn't apply to them because they spoofed a browser user-agent (or another user-agent that a site explicitly allows). So perhaps we have a new mechanism, or new laws, or new... something.
But this all just highlights the point I'm making here: there is no reasonable mechanism (no, login pages and http auth don't count) for site owners to restrict access to their site based on these sorts of criteria. And that's a problem.