Even with that a few of the pages are still essentially lost however - or at least I was never able to retrieve them. Kyunghyun Cho hosts a copy of the processed data on his site at NYU - who may be less likely to receive legal requests compared to Google or a similar commercial company hosting them.
Distribution of datasets is going to be a continued painpoint for machine learning in the future. No-one wants to be the legal guinea pig for exactly what entails fair use in ML.
P.S.: Also, archive.org retroactively removes (or delists?) site content when blocked by robots.txt, as domain parkers often do, so I could see that causing trouble down the line. https://archive.org/post/1019415/retroactive-robotstxt-remov...
Would a fuzzy hash, like the output from a known and fixed classifier work for that?
still thinking about a soft hash.
Google included specific legalese on this very issue. See https://news.ycombinator.com/item?id=12616012