If the users chooses what they are shown and the order they are shown in, then it's fine. If the platform chooses, then it's not, because they will always choose what creates the most engagement.

Not necessarily. Just fix the algorithm. Showing all submissions by time should be ok, showing all submissions by number of upvotes should be ok if the user chooses that.

The platform can also add ghost upvotes and downvotes and censor upvotes and downvotes.

That could be penalized, ultimately by breaking up the company and selling it in parts.

Well, yeah, it could be. Is that your proposal?

I think I would be fine with a positive enumeration. Some ideas for serving content:

    - purely random
    - sponsored but without user tracking (like old school TV ads)
       - sponsored for user selected geographical area feed
       - sponsored for user current location geographical area feed
    - follow "friends" or influencers
    - purely timeline

    - discussion boards
      - timeline (IRC like)
      - threaded
      - user votes (not magic platform votes)

    - follow keywords

So Hacker News wouldn't be allowed?

I think it should be, maybe I'm missing some aspect, I just cooked up a simple list of rules on the spot, sheesh :-D

Edit: huh, I'm probably stupid, but can you explain more?

HN uses magical platform votes.

And it should be transparent about it. When Dan uses a magic lever, it should be visible.

Would Facebook be okay if all the Nazi propaganda posts were tagged "Facebook boosted this post"?

If they did boost it, why shouldn't they tell us?

Would that be all that's required to make it okay?

No, I don't think so.

Is heroin the same as beer? Who even knows.

That's the problem, recommendation algorithms on networks beyond a certain scale should be publicly auditable.

If they're not, I should be able to opt-out of them.