Who buys and controls the CCTV? Back to contents 74 Mass surveillance has a chilling effect on people. The awareness of being watched and tracked prevents people from freely expressing thought or practising their religious beliefs in public spaces. It also compels people to alter their behaviours – particularly in their political life – out of fear of being harassed, hurt, or arrested. What’s worse, such surveillance has a disproportionate impact on historically disadvantaged groups including ethnic and religious minorities, and the poor.