Causally pathological spacetimes are physically relevant
  We argue that in the context of string theory, the usual restriction to globally hyperbolic spacetimes should be considerably relaxed. We exhibit an example of a spacetime which only satisfies the causal condition, and so is arbitrarily close to admitting closed causal curves, but which has a well-behaved dual description, free of paradoxes. 
Veronika E. Hubeny, Mukund Rangamani, Simon F. Ross