[pmontra]

They can ask. A court order to reveal your password is enough. If you don't comply you usually run into troubles. This Wikipedia page http://en.wikipedia.org/wiki/Key_disclosure_law explains how it works in some countries.

There has been a ruling about that in the USA recently http://blogs.wsj.com/law/2014/06/26/mass-supreme-court-defen...

[TheLoneWolfling]

So how does that work if you are using an encryption method that allows plausible-deniability?

"Legally, you must give us the key which probably does not exist"