"I don't mind giving up some privacy for safety. I've got nothing to hide."
"Well privacy isn't something you can just give up. It's a right given to society by our framers, not individuals. A smoothly functioning democracy depends on dissent, which requires privacy to allow alternate points of view to gain traction. So privacy is a social good, not a personal right, and if we reduce privacy, we are reducing our democracy. The Soviets didn't have privacy. Free countries must."
That last part is usually what does the trick.