Fugitive secrets-leaker Edward Snowden made a rare video appearance Monday at the South by Southwest Interactive Festival in Austin, Texas, condemning mass government surveillance and urging members of the tech-savvy audience to take action against it.

Speaking from Russia, where he was granted asylum, the former National Security Agency contractor said "absolutely, yes" he would leak secret government information again. Snowden has been charged with espionage for releasing a trove of intelligence-gathering secrets.

In an hour-long talk he said that the U.S. government's mass surveillance failed to catch the Boston Marathon bombers and warned that governments have created an adversarial climate on the Internet. 

"They're setting fire to the global Internet, and you guys in the room are the global firefighters," Snowden said.

Snowden appeared against a backdrop of the U.S. Constitution with "We the people" written in large letters. The video feed was broadcast on a large screen before several thousand credentialed festival attendees in two conference halls and streamed live online. 

Moderating the discussion in Austin were Snowden’s American Civil Liberties Union attorney, Ben Wizner, and Christopher Soghoian, principal technologist with the American Civil Liberties Union's Speech, Privacy and Technology Project.

Snowden took questions from moderators and those relayed from spectators in the United States and overseas through tweets to #asksnowden. 

The first question came from Timothy John Berners-Lee, a British scientist known as the inventor of the World Wide Web, who asked Snowden how he would create an accountability system for governance.

“We have an oversight model that could work. The problem is when the overseers are not interested in oversight,” Snowden said. “The key factor is accountability.”

“We need public advocates, public representatives, public oversight,” he said, including “a watchdog that watches Congress.”

He believed the lack of accountability will have international consequences.

“If we allow the NSA to continue unrestrained, every other government will accept that as a green light to do the same,” he said.

Soghoian praised Snowden for leaking evidence of government surveillance of private communications and holding the companies who were complicit accountable.

“We have Ed to thank for that,” he said, to loud applause.

Snowden said he was not against businesses such as Facebook and Google collecting data -- responsibly.

"You should only collect the data and hold it as long as necessary for the nature of the business," he said.

He said he had no regrets about leaking classified information.

“I took an oath to support and defend the Constitution,” Snowden said, “The interpretation of the Constitution had been changed in secret from no unreasonable search and seizure to any seizure is fine.”

Because of his leaks, he said, “we’re going to have a better civic interaction as a result of understanding what’s being done in our name.”

Wizner noted during Snowden’s appearance that Rep. Mike Pompeo (R-Kansas) wrote to organizers beforehand urging them to cancel the event, saying that “the ACLU would surely concede that freedom of expression for Mr. Snowden has declined since he left American soil.”