And, certainly, the American people themselves seem predisposed to trade privacy and liberty for even the illusion of safety, as evidenced by what we'll put up with at airports and virtually every opinion poll on the subject. A solid majority (56 percent) in a Washington Post-Pew survey taken after the NSA story broke support the program and a whopping 62 percent "think [it] is more important right now for the federal government to investigate possible terrorist threats, even if that intrudes on personal privacy."
The judicial branch, meanwhile, has been a steady if slow check on some of the most egregious civil-liberties abuses. For example, Hamdi v. Rumsfeld (2004), Rasul v. Bush (2004), and Boumediene v. Bush (2008) reaffirmed the rights of due process for those accused by the executive of being enemy combatants.
At the same time, it's reasonable to wonder how effective a check the Foreign Intelligence Surveillance Court has been. It "approved all 1,506 government requests to electronically monitor suspected 'agents' of a foreign power or terrorists on U.S. soil" in 2010 and "did not deny any applications in whole, or in part." Indeed, they've "declined just 11 of the more than 33,900 surveillance requests made by the government" between 1979 and 2012, an approval rate of 99.97 percent!
But the notion that they are a "rubber stamp" is overblown. While they operate in secrecy, making monitoring their activities next to impossible for those of us outside the system, the court is comprised of 11 U.S. District Court judges appointed by the chief justice of the Supreme Court for seven-year terms. They're real Article III judges, not cronies of the administration or the intelligence services.
The ACLU's Timothy Edgar argues that it's the professionalism of the requests that accounts for the high approval rate. The Justice Department lawyers who draft the requests are "very reluctant to get a denial" and therefore essentially act as in-house judges, seeing themselves "not as government advocates so much as neutral arbiters of the law between the executive branch and the courts" and therefore "getting the order approved by the Justice Department lawyers is perhaps the biggest hurdle to approval." Additionally, while the FISA judges almost never reject these requests, they do occasionally modify them.
It's worth noting, too, that the version of this program that started under the Bush Administration was done without bothering to consult the FISA Court, under the theory that the Patriot Act authorized the president to make the call unilaterally. And that Congress enthusiastically backed that move years after the fact once the news came out.
Then again, the law itself makes approval of these massive requests pretty easy. The metadata in question in this program does not require a high bar at all because our regular courts decades ago ruled that there was a very low expectation of privacy to the fact of conversations, even in ordinary criminal matters; it's only the content of the conversations that requires a high burden of proof.