We consider Lorentz violation in supersymmetric extensions of the standard
model. We perform a spurion analysis to show that, in the simplest natural
constructions, the resulting supersymmetry-breaking masses are tiny. In the
process, we argue that one of the strongest bounds on Lorentz violation in the
photon Lagrangian, which comes from the absence of birefringence from distant
astrophysical sources, does not apply when Lorentz violation is parametrized by
a single vector.Comment: 13 pages. v3: some comments and a short appendix added to elaborate
on the relation between LV and SUSY breakin