Imagine if anyone was legally allowed to create their own fork of Reddit, or Google Groups, preserving the original content, and even being able to post new content through the fork, as if they did it directly. If google decided to ban some content, the fork could easily show it from a backup, leading the users to quickly flee the over-restrictive platform to the fork with the most reasonable moderation.
As a nice side effect, this would kill the rotten ad-based revenue model where everything is free, but your data is sold to the highest bidder. Ad-blocking forks would quickly take over the originals, so in order to be profitable, the original platforms would have to charge the costs to the users directly (or to the forks that would pass them to the users with a possible markup for their added value).
That said, it would be completely against the interests of the VC crowd that wields considerable political influence, so I cannot imagine this happening in the U.S. Europe is another story though.