Snowden appeared at a #CatoSpyCon, and cited evidence of how things have improved since his disclosures (dislaimer: as Libertarian, I'm a fan of both CATO and Snowden). He cited some pretty compelling graphs, such as a sharp increase of SSL encryption. However, at the moment, I'm pretty sure he's made things worse.
The thing is, governments didn't know such surveillance was possible. Now that Snowden showed what the NSA was doing, governments around the world are following that blueprint, dramatically increasing their Internet surveillance. Not only do they now know how to do it, they are given good justifications. If the United States (the moral leader in "freedoms") says it's okay, then it must be okay for more repressive governments (like France). There is also the sense of competition, that if the NSA knows what's going on across the Internet, then they need to know, too.
This is a problem within the United Sates, too. The NSA collected everyone's phone records over the last 7 years. Before Snowden, that database was accessed rarely, and really for only terrorism purposes. However, now that everyone else in government knows the database exists, they are showing up at the NSA with warrants to get the data. It's not just the FBI, but any department within the government who thinks they have a need for that data (e.g. the IRS). Recently, an amendment was added to the Intelligence Authorization bill to codify the process. We don't have any transparency into this, but it's a good bet that the database has been accessed to retrieve American information more often in the year since Snowden than the 7 years before.
Snowden did the right thing in exposing phone surveillance, of course. My point isn't to say he's wrong. Instead, my point is that we aren't winning the war against surveillance. Activists are focussing on the good news, cherry picking the parts where we win. They are ignoring the bad news, that we are losing the war. The Intelligence Authorization bill is an excellent example of that.