Jihadists are very active on Twitter but their accounts frequently get suspended. A substantial debate over the effectiveness of suspension has arisen; an important factor is that Jihadists quickly create new accounts, resurging back like a game of whack-a-mole. This causes biases for terrorism and intelligence analysts. Whilst widely acknowledged, little research addresses the problem. In this study we identify resurging Jihadist accounts with novel methods, and provide detailed analysis going beyond previous case-studies. We show that suspension is less disruptive to terrorists than previously thought, whilst the bias and disruption caused to terrorism research has been underestimated
