  Dark matter collisions with heavy nuclei (Xe, Ge, Si, Na) may produce recoils
observable at direct-search experiments. Given that some of these experiments
are yielding conflicting information, however, it is worth asking if physics
other than dark matter may produce similar nuclear recoils. We examine under
what conditions an atmospherically-produced neutral particle with a relatively
large magnetic dipole moment could fake a dark matter signal. We argue that a
very definite flux could explain the signals seen at DAMA/LIBRA, CDMS/Si and
CoGeNT consistently with the bounds from XENON100 and CDMS/Ge. To explore the
plausibility of this scenario, we discuss a concrete model with 10-50 MeV
sterile neutrinos that was recently proposed to explain the LSND and MiniBooNE
anomalies.
