> One real danger of putting all historical video media on streaming sites is that it makes it far too easy to introduce an Orwellian Ministry of Truth that is empowered to rewrite the past to make it conform to today's acceptable social norms, academic ideologies, government agendas and so on.

I see such rewriting of the past, or at least attempts of that, on Wikipedia. It's not really hidden as there is a (hopefully!) integer edit history, but who reads the edit history anyway? Usually you just look at articles as they are at the current moment.

As we don't have much "hard copies" of a lot of stuff any more around the possibility to "rewrite the past" for significant amounts of people becomes a real thread as we rely more and more on digital and purely online data.

Given how "durable" our digital data is future historians will have a very hard time. Maybe our time will become a dark age when seen form the future. Have you tried lately to open some files from the 80'es that reside on some storage medium form that time? And that's only a few years in the past. Imagine 500 yeas in the future. What will be left of all the cat videos on YouTube (and maybe some more important data)?