ABSTRACT
In today’s ‘pre-crime’ 1 society it is easy to understand the appeal of a technology that promises to identify terrorist plots and stop attacks before they happen, even when the would-be perpetrators have never previously attracted the attention of the authorities or aroused any suspicion (‘unknown unknowns’, in Rumsfeldian terminology). 2 Such claims are not merely the stuff of Hollywood movies such as Minority Report orTV shows like Person of Interest. Mass dataveillance programmes, which have been the subject of much discussion and controversy since the Edward Snowden revelations of 2013, 3 now claim to offer this degree of predictive potential.
