  We consider the effects of magnetic impurities on the surface of
superconducting Cu doped $Bi_{2}Se_{3}$ in the odd parity pairing phase which
support topologically protected Majorana fermions surface states with linear
spectrum. We show that a single magnetic impurity on the surface may induce a
pair of in-gap localized bound states. The energy of the in-gap state is
extremely sensitive to the orientation of the magnetic impurity due to the
so-called Ising properties of Majorana fermions. The magnetic impurity induced
spin-texture, which can be measured using spin sensitive STM, is calculated. We
also show that the RKKY interactions between magnetic impurities mediated via
the Majorana fermions are always ferromagnetic and dense enough magnetic
impurities will develop long-range magnetic order and break the time-reversal
symmetry on the material surface eventually.
