[hamburglar]

I'm within my rights if I write a bunch of jibberish on a piece of paper which represents some secret coding of my personal thoughts, and I refuse to tell you how to decode it. The government can get a warrant allowing them to look at that piece of paper, but as far as I know, they have never had the ability to compel me to explain how to interpret it.

In my opinion, encrypted data should effectively be treated like secret thoughts you may or may not reveal to others or something you've hidden so well nobody will find it. They can analyze the ciphertext, and they can attempt to use surveillance techniques to get you to reveal your secret/key/hidingplace, but compelling you to help them get those things goes too far.