To make people realize the possible consequences of surveillance.
One of the assumptions is that the people aren't completely aware of the extent of surveillance. They assume it's simple as "someone listening to my phone call to my mom" or something as innocent. Something like that hardly has consequences for them, but something like piblishing their private information and data surely has. If they have nothing to hide, they should be all okay with this. If they aren't however... then they should not be supporting surveillance.
What did I miss?