Every other day some minor celebrity complains of being ‘trolled’ on social media. The answer is to get off social media. Twitter is not the real world and can be safely ignored. This is common sense but how about those who have no common sense, and stake themselves out on Twitter so others can throw rocks? Why do we call the rock throwers ‘trolls’? ‘Troll’ started as a piece of Old Norse mythology – where ‘troll’ meant vicious dwarfs or imps, supposed to inhabit caves or subterranean dwellings.