I haven't read their book, but Haidt and Lukianoff contend here that the "like" and "retweet" buttons have been bad for democracy. Currently at Seabird, we have a like button, but it's a private signal to the poster; hat tips and post limits also put a little more sand in the gears than a retweet.
Haidt and Lukianoff: The Polarization Spiral
persuasion.community