If you have never been to London before, you may not know that there are more than 500,000 closed circuit surveilance cameras watching the general public. A featurette for the upcoming thriller Closed Circuit examines the notion of being watched at all times, with director John Crowley revealing how this aspect evolved throughout the production, including the opening sequence where viewers see numerous camera feeds at the same time. We also hear from stars Eric Bana and Rebecca Hall, who speak about how this aspect affected their performances.