(This reminds me of, and not to be political. This is a technological, rather than political angle) There's a TED talk by Carole Cadwalladr about "Facebook's role in Brexit" in which she talks about the ads the Leave campaign ran. This is what is meant by Facebook's "breaking democracy", where campaigns don't have to go through the usual disclosure avenues

Are there reasons why Brexit might have been popular? Yes, in the sense I've heard about them. Should we then be blaming Facebook?

The problem is consolidated power. Carole herself said in her talk that it's not about Trump vs no Trump (sorry. It's been a bit since I've seen the talk. I shouldn't just paraphrase), it's about citizens' right to meaningfully choose in an information landscape

This is the problem with Facebook. It becomes an Everything App. Who cares about fraud (say, on marketplace, needless to say the site itself, the way it's screwed over businesses) on the platform when you can grow big? Let's say in this case, the actual case I'm commenting on - "Facebook didn't know". Well then that's the problem, isn't it? It's a company set up by someone of low moral reasoning (https://news.ycombinator.com/item?id=1692122) that doesn't set out to make a good product, something people will actually like. It's about dominating an industry and ads can be totally unvetted or scummy or scammy if it enables them to do this