Gotcha. Well, I'm not really sure. Maybe just making likes private or banning likes (as suggested in the talk).

Or banning political advertising completely (see the part in the talk on political parties in Germany buying likes).

Or something that completely destroys meddling and fraud and is observable by the public. The "we are working on it behind the scenes"-response is just not sufficient in my view.

You could go down the route of what Slashdot did back in the day. "Likes" were something you could only give out after getting them. So you merely passed them along (like money in a market, sorta). And getting those likes was difficult and hard to game. It was a sort of "pay it forward" system with random batches of "likes" being seeded into the community based on some sort of measurable behavior, after which the community would recycle it internally based on the like being a token of "reward".

Whereas with current social media. Likes are given to users with out any care other than "hey you seem to be a valid user, let's allow you to generate large amounts of likes".