SAN FRANCISCO (MarketWatch) -- Whistleblower Edward Snowden on Monday said companies like Google Inc. and Facebook Inc. had an “ethical obligation” not to cooperate with the National Security Agency data-gathering program, arguing that the tech giants had enough clout to resist the agency.

Snowden, a former government contractor who leaked classified NSA documents related to a secret data-gathering program, took part in a live chat through the Guardian newspaper, which broke the story about the spying scandal.

Snowden said the denials by Google GOOG, -1.66% and Facebook FB, -3.30% about their involvement in the data-collection program were “misleading,” but said the scandal has shed more light on what was going on.

“As a result of these disclosures and the clout of these companies, we’re finally beginning to see more transparency and better details about these programs for the first time since their inception,” he said.

Edward Snowden, a former government contractor who leaked top-secret documents about the U.S.’s data-collection program. Getty Images

He noted that the big tech companies were “legally compelled to comply and maintain their silence in regard to specifics of the program.”

But he also suggested the companies had enough clout to resist.

“If for example Facebook, Google, Microsoft MSFT, -1.04% , and Apple AAPL, -1.59% refused to provide this cooperation with the Intelligence Community, what do you think the government would do? Shut them down?” he asked.

Major Internet companies, led by Facebook and Google, quickly denied being involved in the secret program called Prism, although these denials have been met with skepticism given federal laws that could compel them not to disclose information on government requests.

But both companies also pushed for more transparency over government data requests. Facebook, Microsoft and Apple have disclosed getting thousands of requests, after securing permission from government authorities.

Are we in a cyberwar with China?

“The government will only authorize us to communicate about these numbers in aggregate, and as a range,” Facebook said on Friday. “This is progress, but we’re continuing to push for even more transparency, so that our users around the world can understand how infrequently we are asked to provide user data on national security grounds.”

In the live chat, Snowden also stressed that he “did not reveal any U.S. operations against legitimate military targets,” saying the NSA hacked civilian infrastructure, including “universities, hospitals and private businesses.”

“These nakedly, aggressively criminal acts are wrong no matter the target,” he said.

Snowden also strongly denied that he is spying for China, saying, “I have had no contact with the Chinese government. Just like with the Guardian and the Washington Post, I only work with journalists.”

“If I were a Chinese spy, why wouldn’t I have flown directly into Beijing?” Snowden, who was in Hong Kong when the spying scandal broke, also said. “I could be living in a palace.”