The recent scary clown mask craze has a retro-whiff about it. Rather than people being hounded by trolls on the information super-highway, they are being menaced by clowns on the streets of their neighbourhood. Although an ancient art, clowning has a great deal in common with trolling in particular the use of the mask. All clowns put on a mask, of course, as a method of distancing themselves from their day to day personality, and also as a licence to behave on the edges of acceptability. Trolling too is a form of mask-making. While it is hard to define precisely what trolling is, my millennial students reliably inform me it is not so much bullying on line as taking on an exaggerated persona to get the most effect: being excessively insulted by something, being overly violent in your online responses, taking up exaggerated positions on topics and so on. When you toll someone you use the anonymity of digital masking to create...