No, I don't think it amounts to persecution by the standards of what happened within the eastern bloc during the Cold War.

Snowden is not being persecuted for his views or criticism of the government.

He is being chased because of his intentional theft of classified government documents. Can you name a country in which that would be legal?

The USA on May 11, 1973. (OK, the ruling was not exactly innocent. But Daniel Ellsberg walked free after intentional theft of classified government documents.)

Sorry to have a somewhat real answer to a rhetorical question.

It's an informative answer. Ellsberg remained on US soil and handed himself in to a US court. The court acquitted him.

Now consider how he would have been viewed by the US if he'd instead flown to Moscow and applied to Brezhnev for asylum.

Obviously. We were in an acknowledged but undeclared global war with the Soviet Union. We're not with Russia.

To me the more interesting change is that Ellsberg believed (correctly!) that a story like his could go to US media and would get out. Today nobody trusts the US media to report critically on the USA. (Hrm. If the 2000 election were to happen today, once the Guardian began digging up evidence of concrete, massive, and clearly illegal suppression of black turnout in Florida, would that get reported in the NY Times? Or on something that big would they maintain silence again until it was a mere footnote months later about the state of Florida having admitted to it, been sanctioned, and having promised to not do it again?)