Before 2014's Russian aggression towards Ukraine, several Crimea-related pages pointed out (with citations) that Crimea tried to split from Ukraine twice already during soviet times, but this whole narrative was steadily rewritten after 2014.
Considering how many people rely on Wikipedia to get "facts", this has always struck me at how much history rewriting can happen and how much can it influence the world we live in.
Now, I'm no historian, and I didn't live in Crimea in the 70s, I have no clue what happened there but the whole edit war about Crimea-related pages made me really think about how little and how potentially distorted (in multiple ways) information can be even for recent events.
I think The Office put that beautifully when Michael Scott says:
“Wikipedia is the best thing ever. Anyone in the world can write anything they want about any subject. So you know you are getting the best possible information.”