  We consider constraints on simplified models in which scalar dark matter
annihilates to light charged leptons through the exchange of charged mediators.
We find that loop diagrams will contribute corrections to the magnetic and
electric dipole moments of the light charged leptons, and experimental
constraints on these corrections place significant bounds on the dark matter
annihilation cross section. In particular, annihilation to electrons with an
observable cross section would be ruled out, while annihilation to muons is
only permitted if the dominant contributions arise from CP-violating
interactions.
