It's kind of been a shallow year for both books and movies in terms of impact on me. That's not to say it's been a bad year for them, but it's mostly been just 'enjoyable'.
That said, it was probably Radicalized by Cory Doctorow. It's a collection of four novellas that follow different characters pushed into different kinds of extremist action. The one where people start murdering health insurers was particularly heavy.
I've unsubbed from any comms that had them. They all become ghost towns with zero discussion.