(Sorry for the late response.) Well it depends a lot on the site. Since I focus on books and scholarly articles, the ideal way is to find the URL of the original PDF. The website might show you just individual pages as images, but it might hide the link to the PDF somewhere in the code. Alternatively, you might just obtain all the URLs of the individual page images, put them all into a download manager, and later bundle them all into a new PDF. (When you open the “inspect element” window, you just have to figure out which part of the code is meant to display the pages/images to you.) Sometimes the PDFs and page images can be found in your browser cache, as I mention in the OP. There’s quite some variety among the different sites, but with even the most rudimentary knowledge of web design you should be able to figure out most of them.

If need help with ripping something in particular, DM me and I’ll give it a try.

I never said I follow the law, I’m just wondering what the law says ;)

Honestly much of your reply is confusing me and doesn’t seem to be relevant to my questions. This is what I think is crucial:

Just because a file is cached on your device does not mean you are the legal owner of that content forever.

What does being “the legal owner forever” actually entail, either with regards to a physical book or its scan? And what does that mean regarding what I can legally do with the cached file on my computer?

Came here to post this.

Yeah I’m wondering as well. It seems to save webpages, whereas the issue is with scanned books which may be removed from IA…

, it’s a salty article

Actually the author himself is somewhat harmed by this situation. I would be salty too. When I wish to write my CV, I can say: my text have been published at X and Y. Especially nice if it’s an important and well known publication. Now a part of his CV is literally erased, he can’t access his own texts anymore (not even on Internet Archive). That’s… utterly ridiculous. It’s a common practice to send the author a copy (or multiple) of the text he has published, he has every right to own a copy of them. Now the copy that was intended to be available to everyone is not available even to him. Something of the sort really has happened to me too when a website I published an article on a site underwent a redesign and now the text just isn’t available anymore. Admittedly it’s still on IA, but it’s an awkward situation.

You’ve put it out there for free, though, and the data literally ends up on my machine because you made it do that, so what’s the problem with me saving the data on my machine for later, and potentially sharing it elsewhere for free again?

then publishing it as your own is theft

1. This scenario (misattribution of content) has nothing to do with the previous discussion. The other commenter is making an analogy to CDs, owning a CD and lending it to others doesn’t mean you’re claiming its content is your own creation.

2. Theft implies deprivation of ownership. Calling this theft is like calling piracy theft. It may be illegal by this or that metric, but it’s not normal theft.