Perhaps a bit out-of-date now (but only a little), but an interesting introduction to the allure and consequences of conspiracy theories with a heavy emphasis on the far right. Thankfully includes ideas for deradicalisation. Perhaps also, there could have more more written about who stands to gain from promulgating conspiracy theories as it's bloody obvious that these don't arise in a vacuum. Gains a star for talking to media researcher Mike Caulfield and mentioning the SIFT technique for evaluating information sources, which is far more useful than the CRAAP test.