But it is a mistake (albeit a common one) to survey the NSA-surveillance controversy and to conclude that Greenwald represents the radical position. His writing can be acerbic, mordant, biting, trenchant, scathing, scornful, and caustic. He is stubbornly uncompromising in his principles, as dramatized by how close he came to quitting The Guardian when it wasn't moving as fast as he wanted to publish the first story sourced to Edward Snowden. Unlike many famous journalists, he is not deferential to U.S. leaders.

Yet tone and zeal should never be mistaken for radicalism on the core question before us: What should America's approach to state surveillance be? "Defenders of suspicionless mass surveillance often insist ... that some spying is always necessary. But this is a straw man ... nobody disagrees with that," Greenwald explains. "The alternative to mass surveillance is not the complete elimination of surveillance. It is, instead, targeted surveillance, aimed only at those for whom there is substantial evidence to believe they are engaged in real wrongdoing."

That's as traditionally American as the Fourth Amendment.

Targeted surveillance "is consistent with American constitutional values and basic precepts of Western justice," Greenwald continues. Notice that the authority he most often cites to justify his position is the Constitution. That's not the mark of a radical. In fact, so many aspects of Greenwald's book and the positions that he takes on surveillance are deeply, unmistakably conservative.

He wants to preserve a degree of privacy that Americans have long enjoyed. His antagonists are wielding cutting-edge technology to spy on a scale that has never before been possible. This worries Greenwald in part because he is convinced that humans are too fallible to be trusted with so much power, especially in secret. For years, he has been standing athwart history yelling, "Stop!", even as the people who call themselves movement conservatives worked to destroy Madisonian checks and balances. First Republican and then Democratic partisans have felt that they could trust their own to wield extreme power in secret.

Greenwald has always known better.

So why is he widely considered a radical? In part because the press in America largely refuses to entertain the possibility that the U.S. government itself as taken a radical turn. Under this logic, someone criticizing the Bush and Obama administrations with harsh, extreme language must be the radical. Never mind that since September 11, 2001, the U.S. has tortured prisoners, indefinitely detained innocents without charges or trial, invaded and occupied a country on false pretenses, used the Espionage Act to prosecute more Americans than all former administrations combined, engaged in illegal warrantless wiretapping, and created a clandestine kill list that includes Americans.