Ask HN: Creative Commons license for forum posts and social media?

There has been a lot of discussions about alternative technical solutions (federation, p2p, open source etc) to recent trouble with companies that run various public forums acting in a way that’s not in the best interest of users. Is there an effort to approach the problem also from licensing side? I think one way to approach this could be to create licensing that makes sure users have possibility to take their posts and migrate if the platform tries to lock in user content too much.

Key points could be possibility to freely access your public posts via api. Possibility to migrate your own data by downloading and uploading it to new platform. Opt-in for allowing data to be used for AI training (think art forums). Perhaps possibility for user to redact data later (social media style posts).

At the same time this license could grant platform the basic rights to display and handle data to allow them to operate.

I appreciate non of the current companies would be interested in giving up their data, but going forward I think content generating users should lever their power and negotiate better deal with future platforms.