  We review our recent theoretical results about inequivalence between passive
gravitational mass and energy for a composite quantum body at a macroscopic
level. In particular, we consider macroscopic ensembles of the simplest
composite quantum bodies - hydrogen atoms. Our results are as follows. For the
most ensembles, the Einstein's Equivalence Principle is valid. On the other
hand, we discuss that for some special quantum ensembles - ensembles of the
coherent superpositions of the stationary quantum states in the hydrogen atoms
(which we call Gravitational demons) - the Equivalence Principle between
passive gravitational mass and energy is broken. We show that, for such
superpositions, the expectation values of passive gravitational masses are not
related to the expectation values of energies by the famous Einstein's
equation, i.e, $m_g \neq \frac{E}{c^2}$. Possible experiments at the Earth's
laboratories are briefly discussed, in contrast to the numerous attempts and
projects to discover the possible breakdown of the Einstein's Equivalence
Principle during the space missions.
