Hong Kong, though part of China, is partly autonomous and has a Western-style legal system that is a legacy from the territory's past as a British colony. A U.S.-Hong Kong extradition treaty has worked smoothly in the past. Hong Kong extradited three al-Qaeda suspects to the U.S. in 2003, for example.
But the treaty comes with important exceptions. Key provisions allow a request to be rejected if it is deemed to be politically motivated or that the suspect would not receive a fair trial. Beijing may also block an extradition from Hong Kong for national security reasons.
Snowden told the newspaper he believes the government could try to charge him with treason under the Espionage Act, but Zaid said that would require the government to prove he had intent to betray the United States, whereas he publicly made it clear he did this to spur debate.
The government could also make an argument that the NSA leaks have aided the enemy — as military prosecutors have claimed against Army Pvt. Bradley Manning, who faces life in prison under military law if convicted for releasing a trove of classified documents through Wikileaks.
"They could say the revelation of the (NSA) programs could instruct people to change tactics," Zaid said. But even under the lesser charges of simply revealing classified information, "you are talking potentially decades in jail, loss of his employment and his security clearance."
Officials said the revelations were dangerous and irresponsible. House intelligence committee member Peter King, R-NY, called for Snowden to be "extradited from Hong Kong immediately...and prosecuted to the fullest extent of the law," in an interview with The Associated Press Sunday.
"I believe the leaker has done extreme damage to the U.S. and to our intelligence operations," King said, by alerting al-Qaida to U.S. surveillance, and by spooking U.S. service providers who now might fight sharing data in future with the U.S. government, now that the system has been made public.
King added that intelligence and law enforcement professionals he'd spoken to since the news broke were also concerned that Snowden might be taken into custody by Chinese intelligence agents and questioned about CIA and NSA spies and policies.
"To be a whistleblower, there would have to be a pattern of him filing complaints through appropriate channels to his supervisors," said Ambassador John Negroponte, the first director of national intelligence, in an interview with the AP Sunday. "For me, it's just an outright case of betrayal of confidences and a violation of his nondisclosure agreement."
President Barack Obama, Clapper and others have said the programs are authorized by Congress and subject to strict supervision of a secret court.
"It's important to recognize that you can't have 100 percent security and also then have 100 percent privacy and zero inconvenience," Obama said. "We're going to have to make some choices as a society."
- Opinion: Throwing America’s Privacy Under the Bus
- Washington Post: NSA Spying Included Major Internet Giants
- Anonymous' Leaks Alleged PRISM Surveillance Documents
Associated Press writers Phillip Elliot in Washington, Anita Hofschneider in Waipahu, Hawaii, Gillian Wong in Beijing and Raphael Satter in London contributed to this report. 0