I'm OK with a bit of fear mongering if it means that warrantless spying actually becomes an election issue. These tactics have been used to go to war and substantially reduce individual rights; at least this is a cause I can somewhat get behind.
In this case, "the means" are raising awareness to documented fact (that the NSA spies on its own citizens). If that causes fear, then so be it. It should cause fear, because it's scary. People should care about what their government does, and fear is one emotion that leads to caring.
If history has shown anything, it's that the American electorate doesn't get invested in purely intellectual debate. They need some skin in the game.
When those means are merely exercising free speech rights it really isn't a case of ends justifying the means because there's no need to justify.
Free speech doesn't require justification. Plus they're using those free speech rights to keep people ware of a real crime that is being committed and real rights that are being violated.