"Why should I care if they read my emails? I'm not important and I don't do anything wrong. If it helps them catch terrorists, who cares?"
Until this question is answered clearly and effectively, nobody except all those splinter groups represented by so many logos will care about this.
This isn't really all that different; it's just your private communications being observed, instead of your private parts.
"As long as [the IRS] is [accused of] targeting [tea partiers], who cares? Besides from what I know they probably aren't."
... then tell them to fill in those blanks with something else. You might also follow it with this line of reasoning:
"And I trust this party who's running things. And I trust the other guys will never be in power again. Because that would be a healthy democracy, and my guys would never overstep their boundaries."
Hopefully the ironies, contradictions, vulnerabilities, and fallacies are so plain little more need be said, and you can then focus on how to address the issue, since it's agreed there's an issue.
To me your quote sounds like a smoker who has been shown evidence of a history of smoking causing cancer but prefers to ignore it and make excuses because its easier then accepting they need to make a change.
This somewhat answers that!