You're right, it would violate Lorentz invariance, but only for FTL travel. In that sense it is consistent with SR for speeds <= c. I think it's quite easy to

You're right, it would violate Lorentz invariance, but only for FTL travel. In that sense it is consistent with SR for speeds <= c. I think it's quite easy to make such a theory, I'll get around to writing a blog post on it some day :) The main result is that for communication (or travel) faster than c, invariance is broken, and it becomes possible to distinguish the absolute reference frame.