Maybe the good folks at Apple, Mozilla, Brave or Opera could implement this feature in their browsers? They’re looking to increase their percent of browser use - it could encourage people to at least try switching over. Obviously would be popular among the HN crowd for developer documentation, but we could spread the news :)

On the downside I could see this being used by terrible people to delist actual information sources so that they would only ever be served conspiracy theory sites in their searches as well.