Ariel Toaff is a Jewish professor of Medieval and Renaissance History who provoked death threats following the publication of his latest book. The article focusses exclusively on the last book, linking to every negative comment printed against both him and the book. Basically the book puts into some context why the 'Blood Libel' against Jews gained a hold in various parts of Medieval Europe imbued with ideas of magical practices and talismans, but not in others that were similarly being persecuted. The book seems to portray a community under severe pressure from their Christian neighbours and how that communities developed internal defences to it.
Ariel Toaff's response to the academic criticism is here and an English translation of the book is here.