Re: Oracle--the official database of the Five Eyes!!
Not only were the Tsaernaevs on the radar already thanks to a Russian tip off, they also IIRC posted various islamist rants to Facebook. That is, the same Facebook that the NSA has a back door into in order to spot terrorists.
As for Larry's rhetorical question about government misusing information, one needs only look as far as J Edgar Hoover's abuses of his position at the FBI to see how dirt on anyone and everyone can be used.
That is the real reason for NSA surveillance. The Boston bombers killed 3 people. Drink drivers kill more every night in the US.