On official announcements from a municipal government? Yes. Imagine a scenario like...

Foo Town: boil water advisory for Tuesday. The water department has noted a risk of harmful pathogens in tap water and recommends boiling water for 2 minutes before consumption all day Tuesday.

Commenter: It's all those [racial slur]s shitting in the reservoir. If that [expletive] police chief doesn't run them out of town, we're going to have to round them up and shoot them!

Assume the commenter has done this enough times to figure out what the platform's moderation will catch and what it won't. The town would probably like to be able to do some additional moderation.

That goes against Facebook policies and the account would get banned. Not to mention that’s a gigantic strawman.