Hidden volumes or steganography have been around for a while for the explicit purpose of 'plausible deniability': https://www.truecrypt.org
And I can say I'm carrying a deck of cards around because I really like playing solitaire in my free time, but its not going to stop the govt from beating me with the boot if they really want to.
https://xkcd.com/538/
And I can say I'm carrying a deck of cards around because I really like playing solitaire in my free time, but its not going to stop the govt from beating me with the boot if they really want to.