This is the tactic used by the CNN / Dailymail dataset[1] released by Google Deepmind. In that situation you want everyone to have the same and original file. The contents of the URL may be updated and/or disappear. The original URLs are recorded but they're retrieved from the Wayback Machine.
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.
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.
[1]: https://github.com/deepmind/rc-data