Max, I would counter that had guns been allowed in cockpits, airport security defederalized, and a more rational immigration policy tightly enforced, 911 and these Canadian incidents wouldn't have happened.
We have a problem with immigration. It's not John Smith or Richard Adams blowing things up. It's Usef Albahadi on a student visa, and Rama Hussein who was naturalized 2 weeks ago. 95% of all North American terrorism is perpetrated by foreign nationals.
As for the NSA, there's a cost to freedom, sure. There's also a cost to invasive Government spying, and rescinding liberty in the name of security. While the NSA may have identified these Canadian terrorists beforehand, it didn't stop the attacks. On the flip side, the NSA is now used to blackmail the executive, judiciary, military and Congressional branches of Government with dirt they find and use to steer the direction of the country. Sort of a shadow Government. Snowden revealed that, as has William Binney (former NSA director, turned whistleblower).
Now to have the entire democratic process thwarted in this country by some military thugs at the NSA, in exchange for identifying a few towel-heads before they pop off their shotguns, never. That's a fool errand and totally dangerous. We're already in red level danger zone with how the NSA operates and has been operating for the past ~20 odd years. It's a gigantic blackmailing operation. ISIS is just theater to keep us distracted from the real issues, at home.