Domestic digital spying on ordinary citizens is an international threat that will only be slowed with measures like a proposed international treaty declaring privacy a basic human right, Edward Snowden said Thursday in a video appearance at a New York City forum.

"This is not a problem exclusive to the United States.... This is a global problem that affects all of us," Snowden, the one-time National Security Agency systems analyst, said in his brief remarks from Moscow via video link.

"What's happening here happens in France, it happens in the U.K., it happens in every country, every place, to every person."

The key question, Snowden added, is: "How do we assert what our rights are, traditionally and digitally?"

Snowden gained worldwide renown in 2013 for leaking thousands of documents with details of extensive, secret U.S. surveillance programs, including a program by the NSA to capture and store data on every phone call made by Americans.

While fleeing, his passport was revoked and he ended up in Russia, where he was granted asylum despite demands by the United States that he return to face espionage and other charges.

The global advocacy group Avaaz organized the gathering to promote the so-called "Snowden Treaty." Countries who sign would be required to curtail surveillance of phone calls and online activity, and also agree to provide sanctuary for people who expose illegal domestic spying.

The forum was timed to coincide with the United Nations General Assembly. Organizers have said diplomats have shown interest in a draft of the treaty, but have declined to name what countries they represent.

Massive eavesdropping

Snowden's revelations of extensive U.S., Canadian and British snooping have been deeply controversial ever since his first disclosures to journalists.

Documents he provided exposed a wide array of secret practices, including that U.S. government agencies essentially were trying to collect every email, phone call, text message and other communication they could get their hands on, that they were eavesdropping on world leaders' cellphones and even tapping undersea internet cables in their efforts to be able to spy on anyone, anywhere.

U.S. President Barack Obama sought, and Congress passed, a law ending the bulk collection of Americans' phone records and instead allowing the NSA to request the data as needed in terrorism investigations. Weeks earlier, a U.S. appeals court had declared the program illegal.

A website promoting the proposed "Snowden Treaty" calls the NSA surveillance programs "a direct contravention of international human right law." It adds: "Protecting the right to privacy is vital not just in itself but because it is an essential requirement for the exercise of freedom of opinion and expression, the most fundamental pillars of democracy."