The 4th amendment says
The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized
That means if the FBI wants me decrypt any of my documents they can show my lawyer a search warrant otherwise they can FUCK OFF. If you want to fight these fuckers you, yes you, can start by teaching other people how to use strong encryption and why they should use it all the time. Yea,the NSA has monster facilities to break encryption but the cost of that is not zero. There are more of us then there are of them.