While biometrics offer more advanced solutions than passwords and PINs, their use on mobile devices is not marketed as improving security over the older methods. Steven Furnell examines examples from the Android and iOS platforms, and considers the degree to which the biometrics are being presented as a means of improving usability of authentication rather than security. The session is taken from a guest lecture delivered at the University of Piraeus on 14 January 2014. [(CC) BY-NC-SA 2.0 UK]