Comment by usr1106
10 hours ago
Sorry, not following. I thought the user agent is a string that the caller can set to anything. There is no immediate, reliable way to tell whether the string is correct.
Yeah, a real browser would produce certain patterns and never certain others. So in some cases one could clearly say it's not a human using a browser. But a scraper could also make efforts to mimic human browsing. Mostly the frequency of requests can tell with high probability tell it's not human. But such algorithms might occasionally give false positives for real users, exactly like it has obviously happened for the archive.
What google service are you referring to? Not sure whether the archove uses any of Google's tracking. I have pretty strong blocking of trackers and ads. But the archive works for me.
Google's scraper bot at least used to be behind IPs that you could identify via reverse-then-forward DNS. Not sure if that is still up to date, though.
https://developers.google.com/search/blog/2006/09/how-to-ver...
Yep, verifying the IPs is still the way to go. You often see websites that do it wrong when you set your user agent to Google Bot and they give you a different version of the page without validating that.