For all my life, whenever someone complained about the government's intrusiveness you could hear someone answer "well, I've done nothing wrong, so I've got nothing to hide." We'll be hearing a lot more of that in the future.
Although this argument is every bit as stupid as "we're fighting them over there so we don't have to fight them here" it's the easier, less painful, one to rebut.
The devastation of "Nothing to hide nothing to fear":
When you were a child, didn't your parents tell you to NEVER tell strangers anything about your household? Why did they do this?
Because they knew that evil-intentioned people can use what they know against you. Knowledge is power, and knowledge about you is power over you.
When you willingly give your information over to a bunch of total strangers, operating in secret, and with who knows what, if any, oversight, and with who knows what dark business on the side or hidden in their soul, you've done a stupid thing. They have power over your identity and over your life, and you have no way to check or counter what they choose to do with it.
Do you think your parents would want you to just give them that? Do you think Americans have died for over 230 years to let someone have that much power over everyone?
So, like all of us in this brave new world, there is something to hide: The keys to our freedom.