If he is in fact a real person whose story has been accurately portrayed, I think Edward Snowden is to be commended, at least for the intent of his warning if not its ultimate effect. However, I'm by no means convinced that either assumption is accurate.
The amount of media coverage on Snowden and the NSA's spying revelations was sky-high. In our corporately coordinated media, that means his story conveyed an important message that was meant to be told. Yes, much of the coverage was to demonize him and call him a traitor, but that's just a vehicle for delivering the core message. Regardless of whether you consider him a traitor or a patriot, you've received the message.
That message -- that all US citizens are being spied upon and monitored by "our" government -- is important to someone. It's important to people who benefit from the current power structure in this country, and want to preserve it for their own benefit.
Such a message is important for maintaining the sense of isolation among any would-be revolutionaries. If you can convince them they're being spied upon, communications cease -- even if you're not actually monitoring them at all. Without communication, nobody realizes how many other people share their views, making the momentum necessary for a revolution impossible to build.
Why do you tell someone that they're being spied upon, instead of simply spying upon them in secret? You do so to stifle the communication between any groups that would challenge the current power structure. It's a form of intimidation. I'm inclined to think that the NSA's actual ability to successfully sort through the billions of daily communications they supposedly monitor is much more limited than we've been lead to believe.
Recent revelations of government torture -- which also received widespread media coverage -- have nothing to do with intelligence gathering, though the argument is always framed as such. People being tortured will say anything (usually inaccurate) to stop the torture, as John McCain once noted from his experience. Advertising your willingness to torture people is simply another form of intimidation -- in this case the intimidation is again directed at US citizens.
Combined with other messages of government torture, extraordinary rendition, or the treatment of whistle blowers, few people would be willing to risk being caught, and thus will never speak their mind. People that don't speak their mind never become revolutionaries. It's the same model that was successfully deployed in the former East Germany, where I visited relatives back in 1985.
Why would the US government (calling it "our" government no longer works for me) have a sudden interest in suppressing any subversive or revolutionary communications? Nobody can predict the future with absolute certainty any more than we can predict the exact weather details for a year in advance of any given day. However, it is quite possible to predict general trends with respectable accuracy, with weather or with human populations. Governments pay attention to these forecasts the way farmers scrutinize weather forecasts.
I once worked with a programmer who had been involved in such modelling for various governments around the world. His company was in high demand, as they took all the data they could gather (resource trends, population dynamics, agricultural output, etc), plugged it into their modeling software, and used it to identify various trends and risks. He was doing this in the late 1970's for Iran, among other countries.
I'd be willing to bet that such modeling has grown dramatically more sophisticated since then. Similar modeling predicted many of the "Arab Spring" revolutions. Based on my understanding of energy resource availability, I'd be willing to bet that it shows some significant upheaval coming to the US in the near future as well.