Verizon and the N.S.A.: The Problem with Metadata : The New Yorker:

But with each technological breakthrough comes a break-in to realms previously thought private. “It’s really valuable for law enforcement, but we have to update the wiretap laws,” Landau said.

It was exactly these concerns that motivated the mathematician William Binney, a former N.S.A. official who spoke to me for the Drake story, to retire rather than keep working for an agency he suspected had begun to violate Americans’ fundamental privacy rights. After 9/11, Binney told me, as I reported in the piece, General Michael Hayden, who was then director of the N.S.A., “reassured everyone that the N.S.A. didn’t put out dragnets, and that was true. It had no need—it was getting every fish in the sea.”

Binney, who considered himself a conservative, feared that the N.S.A.’s data-mining program was so extensive that it could help “create an Orwellian state.”

As he told me at the time, wiretap surveillance requires trained human operators, but data mining is an automated process, which means that the entire country can be watched. Conceivably, the government could “monitor the Tea Party, or reporters, whatever group or organization you want to target,” he said. “It’s exactly what the Founding Fathers never wanted.”