Of course, if Greenwald's information is accurate, logically only the U.S.' s enemies would want the information released, so Shoot My Balls might be wise to be looking more carefully at his "friends" offering him asylum. Additionally, what is being threatened now is far beyond the initial leak of information regarding NSA phone records collection domestically, and involves information that could materially benefit al Qaeda, Iran, North Korea, etc. That's a situation that raises the national security stakes dramatically, and undermines the notion of him being a "hero" for individual liberty.
UPDATE: The estimable tBogg opines on the wisdom of Shoot My Balls' game plan:
"Having made that threat, Snowden, with Greenwald’s help, effectively weaponized himself against the US government by inviting any third party actors, whether the government of a country hostile to the United States or a lone wolf who thinks it would be fun to pop a cap in Snowden’s ass just to see what happens next, to kill him. I’m going to go out on a limb here and suggest that a better plan would have been for Snowden to convey this promise/threat/dramatic posturing to the US government privately instead of getting a target tramp stamp tattooed on his back and then showing it to the world."