It isn’t’ only the Second Amendment that gets in the government’s way–the Fifth is an essential bar when it comes to railroading a citizen in court. You need to know your rights pertaining to it, and it goes further than the Miranda warning we’ve all memorized after hearing it a thousand times on TV. Ars Technica has an excellent piece on passwords, passcodes and when you should and shouldn’t give them up to law enforcement.
Knowledge is power.