Edward Snowden called on supporters at a hacking conference to encourage development of easy-to-use technologies to subvert government surveillance programmes around the globe.
Snowden, who addressed the New York conference via video from Moscow, said he intended to devote much of his time to promoting such technologies, including ones that allowed people to communicate anonymously and encrypt their messages.
"You in this room right now have both the means and the capability to improve the future by encoding our rights into programmes and protocols by which we rely every day," he told the Hackers On Planet Earth (HOPE) conference.
"That is what a lot of my future work is going to be involved in."
The former National Security Agency contractor fled after leaking documents that detailed massive US surveillance programmes at home and abroad.
His revelations outraged some Americans and sparked protests around the globe.
Snowden was granted temporary asylum in Russia, but while addressing the conference he did not discuss the status of a request he made earlier this month to extend his Russian visa, which expires at the end of this month. The US wants Russia to send him home to face criminal charges, including espionage.
At the HOPE hacking conference, several talks detailed approaches for thwarting government surveillance, including a system known as SecureDrop, which is designed to allow people to anonymously leak documents to journalists.
Attorneys with the Electronic Frontier Foundation answered questions about pending litigation with the NSA, including efforts to stop collection of phone records that were disclosed through Snowden's leaks.
Snowden is seen as a hero by hackers attending the HOPE conference, which gives a platform to computer experts, anti-surveillance activists, artists and other types of hackers.
It featured about 100 presentations on topics ranging from surveillance to hacking elevators and home routers.