If you criticize Greenwald and Snowden you are

[Benton D Struckcheon]

14. One more time, the tactic is "poisoning the well".

It's a species of ad hominem attack. Any thread accusing others of being spies for the government simply for the stand they take should be shut down without question, and the person posting it should get, say, four out of five hides' worth as a penalty. This way they're not stopped from posting for a time if they do it, but the penalty is steep enough that no one will do it frivolously, as that one did.
I used to go to a forum where if someone attempted this that person was called out without mercy, even by people who were on the same side in whatever debate was taking place. It's a sad commentary on the culture here that it doesn't happen here. It's even sadder that very few people seem to think it's even wrong, or know what the tactic is and why it's so despicable.