They do when most other countries will extradite them back to the US, where they'll be tossed into a dark cell for the rest of their life.

Snowden did his part. He released the information he had. Assuming we believe the information he released is genuine, it's utterly irrelevant what we think of him now, or what he has to do to survive and remain at least somewhat free.

> Snowden is a traitor.

Pedant hat on: Snowden can never legally be tried as a traitor, as he has not committed treason. The US Constitution very precisely describes treason, and he did not do that. If Snowden were ever arrested and returned to US custody, I imagine the main charges would revolve around espionage and conspiracy.