Pedestrians on Sunday, April 29, 2012, pass gated residential flats in Bow in east London, where the Defense Ministry has warned residents that surface-to-air missiles could be stationed on the rooftop during the London Olympics. (AP Photo/Sang Tan)

Photo by: Sang Tan

Pedestrians on Sunday, April 29, 2012, pass gated residential flats in Bow in east London, where the Defense Ministry has warned residents that surface-to-air missiles could be stationed on the rooftop during the London Olympics. (AP Photo/Sang Tan)