Why is he here, day after day, spamming ideological nonsense? Because there's fewer mainstream places for Menta and the anti-vaxxers to preach, Dex.
Reddit, Facebook, Twitter, community groups, even mother's groups and so on are all becoming aware that their openness and goodwill has been compromised by ideological extremists like Menta and others here, who infiltrate groups and peddle their philosophy of divisiveness and death relentlessly. With varying degrees of success, those forums have enacted policies to keep the nutters and extremists wanting to blow up society out.
HotCopper, as seen with white nationalist activists here before the Christchurch massacre, remains wide open to ideological recruiters. So that's why they're here.
