What can a 500-year-old book teach us about how dangerous ideas spread?

When you picture a witch, the image that springs to mind usually involves women wearing pointy hats and flying around on broomsticks. The reason why lies in a 15th century book.Malleus Maleficarum (The Hammer of Witches) was a manual for how to hunt, torture and execute women accused of witchcraft, and was the catalyst for witch trials that killed thousands of women across Europe. The University of Melbourne's Archives and Special Collections has recently acquired a rare copy. So what can the world's most infamous witch-hunting handbook tell us about the spread of misinformation and dangerous ideas today?