This is just going to be a sad wail - but if they like him, can't they try to persuade him to get help for his persecution complex? Or even just his general health.
He can get away with the paranoid belief that there is one unified global meat trade that exists purely to oppress & kill animals because they're speciesist because it's a marginal topic but paranoia about an Islamist take-over of Europe because they want to destroy the white race or non-believers or cows or women or gays or Christians or whatever group he's most concerned about, feeds into a major political trend & will lead to constant attacks that he's not really built to survive.
I'd be bombarding him with pleas to stop. Which I kind of am - in this internet void.