Well, I have some experience with the Danish National Archives, but may be out of date. First, the rule used to be that they could crawl all Danish sites or ha

Well, I have some experience with the Danish National Archives, but may be out of date. First, the rule used to be that they could crawl all Danish sites or having interest to Danish government (so I guess also news reports of Denmark or discussion in other nations) ignoring robots.txt, which yes I found that to be a very wrong headed rule but that's what it was. So obviously they need to put in a good deal of effort to get content into the archives that would be getting blocked otherwise. At the same time governmental records, including the records and cases in communities around the country get added to archives (but of course are only available to scholars at some future date) So theoretically this is a lot of data. I suppose other national archives probably have similar rules and situations. It would seem unlikely that one could rewrite history easily with so much data, without alerting people to what you were doing. But I guess that is actually the lesson of Fascism, they don't care if you see what they're doing. They will do it and then hope you forget how it got to be like it is.