VOICED: Canada mounts colossal security operation for Winter Olympics

The 2010 Olympic Winter Games in Vancouver saw unprecedented security measures, with 15,500 personnel deployed to prevent terrorism and crime. Despite no specific threats, nearly a billion dollars was spent on security, including military and surveillance systems. Concerns were raised about civil liberties and the effectiveness of such measures, with some viewing it as security theater.

What is meant by 'security theater' in the context of the Olympic security measures?

What concerns were raised by civil liberties groups regarding the security measures?