People can think that they have nothing to hide, but that doesn't mean they haven't broken any laws. If the police or FBI want to find something incriminating, chances are they will. And having the "I have nothing to hide" mentality is what they're counting on. It makes their job easier. I strongly encourage everyone to watch this video to understand just what you're up against when you give the cops what they ask for:
I know it's a long video, but it's so highly informative and entertaining to watch. Especially when they bring the detective to speak. And yes, it's about literally talking to the police, but it extends to allowing someone free access to your personal data. You shouldn't have to do it for the same reason that you shouldn't have to talk to the police. 4th and 5th amendment of the US constitution. Know your rights people, if you have the misfortune of living in that fascist country, you absolutely have to know your rights.
TLR version: any piece of information that the police has on you is
NEVER used to help you. And that is a legal fact. I can't stress this enough. So stop being stupid and stop relying on "I have nothing to hide" mentality. You don't know that.