Additionally, one could argue that as our freedom grows the opportunities for surveillance increase. That is, if you use the same means of communication as available in 1776 you'll have just as much freedom as they did. But in 2013 you have much more freedom to communicate over various mediums. Your freedom has increased by a factor of x, but surveillance has decreased that freedom by a factor of y (where y is much less than x). The net gain is still positive, but less than unsurveilled access.
An interesting thought experiment is how well would an airline that does no security checks do versus one that does. Lets ignore the efficacy of security checks, and say that you're 10x more likely to die in the flight w/o security checks -- would most people be willing to endure the security checks (as they are today) for a 10x reduction in deaths (imagine the baseline is the number of deaths we see today). I think the answer is yes.
Likewise, I may well feel less free if there were no jails (maximizing actual physical freedom for prisoners) than if there is some.
Bravery doesn't equal stupidity. I'm not condoning the actions of the US government, but I think its unfair to assume increases in safety with an actual proportional decrease in freedom.