Although there is no intelligence to suggest a credible and specific threat to the games, officials have spent years taking precautions for the Olympics since London won the bid the day before the 2005 attacks.
Britain is already known as a leader in 'Big Brother' surveillance — there are nearly 30 CCTV cameras near George Orwell's house alone in North London. The author of "1984" warned more than six decades ago of a time when it would be nearly impossible to escape from the watchful eyes of the state.
For the games, more cameras will be added to Britain's 4.3 million, and some will be used in conjunction with advanced facial recognition software and databases that can match vehicle registration numbers to names.
Olympic venues have also been designed with security threats in mind — special shatterproof glass has been installed, structures have been built with advice from explosives experts and pathways have been laden with curves and gaps deliberately meant to slow down a potential attacker.
"If you look at the Internet, there are web sites calling exactly for these types of lone-wolf attacks," said Rob Wainwright, head of The Hague-based Europol, which will be sharing databases with law enforcement officials during the Olympics.
Associated Press writer Steve Wilson contributed to this report from London.