From Jessica Roy at The Cut, a horrific lede:

A British man used social media to stalk a teen in Scotland, then traveled 500 miles to the grocery store where she worked and smashed her over the head with a wine bottle, all because she gave his self-published book a bad review.

Maybe it's time to briefly go over the rules of engagement for authors?

1. Be gracious and brief when you receive praise on social media.
2. Engage with your fans. Be nice and kind and good.
3. Never respond to critics who write bad reviews; you're not going to convince a critic that they actually liked your book, and bystanders will think you're petty.
4. Don't stalk your critics and hit them with wine bottles. In fact, don't hit them at all. Or stalk them. Don't stalk anybody. Don't hit anybody. Don't be a bad person. Be a good person.
5. Rule 4 is the most important one.