The introduction of plausible deniability in encryption is actually the ultimate nightmare from an ethic perspective:

The torturer, of course, knows about plausible deniability. And of course, technically, plausible deniability is not limited to two levels (outer and inner volume), but can be performed on an arbitrary number of levels. From the torturer perspective, he has to continue to torture forever, because any passphrase revealed might not be the one for the "true" stash of information. In reality, the torturer does not stop at the first possible instance of revelation, but on the last (which will never be in this case).

Plausible deniability actually prevents the torturer from rewarding the victim for the revelation of information by ending his/her pain. Instead, plausible deniability opens the spiral of endless violence.