Since the 1970s, security planning has become an integral and required part of bidding documents and preparation for hosting sporting mega events, most notably the summer Olympic and Paralympic Games. Drawing on a multidisciplinary conceptual framework derived from prior experiences of security operations at major sporting events and historical counter-terrorism experiences of London, the paper unpacks the socio-spatial implications of security measures intended to secure the 2012 Games. In particular, it highlights the threat posed against 'crowded places' from international terrorism as well as possible surveillance, design or managerial measures that are to be deployed to make such sites more resilient to terrorist attack. This, it is argued, both converges with standardised Olympic security models and diverges at important points, related to the pre-existence of capacity in urban counter-terrorism onto which 2012 security will be overlaid or laminated. The paper also highlights the increased use made of security for 'legacy' purposes.