The State Must Have Something to Hide

Any terrorist who does not believe that we are living in a free society but under a disguised tyranny (the sort he would like to establish under a different mantle) would have assumed that, at the very least, his phone calls could be logged and his emails read. The only people not to believe so were honest citizens who thought they were living in a free society. So remind me what are the reasons for hiding the Surveillance State? Why do you hide your surveillance programs if you have nothing to hide?