Critics slam him as a traitor. Supporters hail him as a hero.
Now Snowden, who faces espionage charges in the United States, is in Russia and seeking asylum from Ecuador.
U.S. Vice President Joe Biden asked Ecuador "to please reject" the request for asylum, according to Ecuadorian President Rafael Correa.
"That's not acceptable," WikiLeaks founder Julian Assange told ABC's "This Week" on Sunday.
Assange, whose organization facilitates the release of classified documents and is assisting Snowden's asylum bid, said he couldn't reveal details about the former NSA contractor's specific location or the status of his case. He criticized U.S. officials for pressuring Ecuador on the matter.
"Asylum is a right that we all have. It's an international right. The United States has been founded largely on accepting political refugees from other countries and has prospered by it. Mr. Snowden has that right," said Assange. "Ideally, he should be able to return to the United States. Unfortunately, that's not the world that we live in and hopefully another country will give him the justice that he deserves."
Former Cuban leader Fidel Castro weighed in on Sunday. In a letter to Nicaraguan President Daniel Ortega published in Cuban state media, Castro praised Ecuador's president for standing up to U.S. threats over Snowden.
On Saturday night, Correa said the ball was in Russia's court.
"We didn't ask to be in this situation. Mr. Snowden has been in touch with Mr. Assange, who recommended he ask for asylum in Ecuador. In order to process this request, he needs to be in Ecuadorian territory," Correa said in an interview with Ecuador's Oromar TV on Saturday night. "At this point, the solution for Snowden's final destination is in the hands of the Russian authorities."
Russian President Vladimir Putin has said it's up to Snowden to figure out his next step.
"The sooner he selects his final destination point, the better both for us and for himself," Putin said.
A top Russian lawmaker said Sunday that Russia must not hand Snowden over to the United States.
"It's not a matter of Snowden's usefulness to Russia, it's a matter of principle," Alexei Pushkov -- who heads the international affairs committee at the Duma, the lower house of parliament -- said on Twitter.
"He is a political refugee and handing him over is morally unacceptable," he said.