As much as I'd like to disagree with you, I agree. But in the long term I think the trust can be restored, if majority of people can actually give a shit about these revelations. Mostly because NSA can't do the things they do without the support of big companies like Google, Apple, Microsoft etc. Once these companies start losing money and the reason is apparent, they'll take actions against the government as Lavabit and other relatively small sized companies had done (not saying they'd shut down, obviously).
Governments act the way they do because majority of people don't care about any of this stuff, not yet at least. Most people who're uneasy about these revelations are uneasy because of what might happen in the future and they fear how far governments are willing to go (or better yet, can they go any further) to invade our privacy. Today, governments' actions don't effect any of us, not directly at least. It's been the case that people don't act against something unless that thing directly effect their lives.
But maybe it really is too late and the trust can not be restored again. Wealth inequality directly effects the citizens of the US (at least that's how I see it from a foreigners point of view) and the US citizens did nothing to change it, other than OWS movement which was arguably a desperate attempt.