Regardless of what you might think of Snowden, he has a good quip on this: "Arguing that you don't care about the right to privacy because you have nothing to hide is no different than saying you don't care about free speech because you have nothing to say."
Also, I invite anyone who thinks they have "nothing to hide" to put a publicly accessible webcam in their home bathroom. Everyone has things they'd prefer to hide, and that doesn't imply anything nefarious is going on.