This may not be well-known, but archive.org can and does remove pages / sites from the archive. Authors can request this, site owners (separate from the authors

This may not be well-known, but archive.org can and does remove pages / sites from the archive. Authors can request this, site owners (separate from the authors) can request this. There may be others who can request this. Just an FYI. If there are critical sites you want copies of, I'd recommend making your own copy. I've lost access to important pages / sites twice before taking this to heart. Edited for clarity