For all it's doing wrong, the NSA has a goal in mind to try to protect the American people. If its methods become cancerous that is one thing, but factor in the intentions here. They are not trying to ruin lives, even though their perspectives might be warped.
This idea is mistaken because nobody knows what their intents are. Your idea of "just trust them" isn't comforting; quite the opposite.
They are not comparable to Osama bin Ladin. bin Ladin cannot do more than add a tiny increment to the risk that Americans go through every day in life. The government, however, by monopolizing violence, can then use that violence to take away anything that makes life good.
A government that has lost accountability is far more dangerous than a terrorist organization. If you don't believe that, ask those who fled the Soviet Union, or who lived through Saddam's regime in Iraq.
Osama Bin Laden is dead, remember? Who is our enemy now? At what point is the war on terror over -- when do we declare victory?
The problem here is that there is no end to this. It will drag on and on, with more and more freedoms lost as long as people continue to cower in fear like this.
This idea is mistaken because nobody knows what their intents are. Your idea of "just trust them" isn't comforting; quite the opposite.