The international 'data war' that is fought in the name of counter-terror is concerned with mobilising the uncertain future to intervene'before the terrorist has been radicalised'. Within this project, the digital footprint has become increasingly significant as a security resource. At the international border, particularly, the traces of data that cannot help but be left behind by everyday consumption and travel activity are mobilised within 'smart' targeting programmes to act against threat ahead of time. Subject to analytics, rules-based targeting and risk-scoring, this data is believed to offer a fuller picture of the mobile subject than conventional identification information. This paper places the data footprint alongside the history of the conventional criminal 'print' within forensic science to examine the future-oriented modes of governing that are emerging within smart border programmes such as the UK's e-borders. The digital print has less in common with the criminal print as objective evidence of past events and more in common with early efforts in anthropometry and biometrics to diagnose a subject's proclivity ahead of time. In the context of contemporary border security, this is unleashing uneven and occluded governmental effects.