You're exactly right about how our culture of distrust of government has helped avoid Gestapos.
I have never claimed people should let down their guard. I've claimed that people should actually think and reason about an issue and then make a decision, instead of setting up easy (and flawed) rules for hard problems.
I'd be worried if people weren't initially revulsed by stories about government reaching the traditional line at which we declare civil liberties most important. But just as we've moved the line closer to civil liberties and farther away from state power, I don't see how it's automatically totalitarian to even think about moving the line closer to state power if there are actual benefits to be gained and without corresponding higher risk.
Unfortunately it's hard to even debate that here; even where you can get people to agree that it might be possible to consider a risk/reward analysis, they usually take incredible liberties in the logic process.
E.g. the "50 plots foiled; still no details story". It's like, really... you don't think there even 1 possible plot that could only have been detected by grabbing the unencrypted message data from G+/Gmail or Facebook? If someone can't even bother to think critically about aspects contrary to their chosen end state then how can I trust them to debate using critical thought?
I didn't trust Glenn Beck when he tried to use OLIGARHY as a debate tactic; I'm not going to trust people on other issues when they use poor logic either.