Recent years have seen a revival of the heated culture wars of the 1990s, but this time its battle ground is the internet. On one side the alt right ranges from the once obscure neo-reactionary and white separatist movements, to geeky subcultures like 4chan, to more mainstream manifestations such as the Trump-supporting gay libertarian Milo Yiannopolous. On the other side, a culture of struggle sessions and virtue signalling lurks behind a therapeutic language of trigger warnings and safe spaces. The feminist side of the online culture wars has its equally geeky subcultures right through to...