From the comments in “Reddit LARPs as h4x0rz News”:

If they ignore robots.txt there should be some kind of recourse :(

Error 403 is your only recourse.

Bingo - forbid them from accessing your content.

And in the meantime make robots.txt legally enforceable across multiple countries.

For antisocial scrapers, there’s a Wordpress plugin, https://kevinfreitas.net/tools-experiments/

This looks fun. I wish I thought about it before writing my shitty idea.