[someone13]

See, here's the issue. The burden of proof, in our court system, lies with the prosecutor. If I could just say "I know you killed that person, so bring me to the murder weapon and body", and charge the accused with contempt of court if they said "no", then there's a massive potential for abuse. For example, if the accused didn't actually do it, then they would get charged with contempt (or obstruction, or whatever), because they have nothing to show.

Passwords to encrypted containers are slightly different - they're not as simple as a key to a safe, and not as obviously protected as my above (contrived) example. However, the same problem exists. If I compel you to decrypt an encrypted volume, and you don't actually have the password (i.e. it's a friends', or whatever), then it's similar enough to the example above.

I'm not a lawyer, nor am I well-versed in law. But I know enough to say that it's not nearly as cut-and-dried as some people think.