  Although it is widely accepted that `no-broadcasting' -- the nonclonability
of quantum information -- is a fundamental principle of quantum mechanics, an
impossibility theorem for the broadcasting of general density matrices has not
yet been formulated. In this paper, we present a general proof for the
no-broadcasting theorem, which applies to arbitrary density matrices. The proof
relies on entropic considerations, and as such can also be directly linked to
its classical counterpart, which applies to probabilistic distributions of
statistical ensembles.
