In a thread some time back on black hole firewalls, one of the papers linked to was one by Bousso in which he argues that (as the paper is titled--note that this is a revised version, the original was quite a bit dfiferent) "Complementarity is Not Enough". I'm not trying to start a general discussion on the various points of view on this topic; I am looking for the thoughts of any experts here on one particular point in the paper that I'm not sure about. On p. 2 of the paper, Bousso presents the argument for why, if the equivalence principle is correct, quantum states outside the horizon must be (nearly) maximally entanged with quantum states inside the horizon: I've bolded the part I am not sure about. I agree that the region outside the horizon, B, can be identified with the right Rindler wedge. But the argument given in the above quote also requires that the region inside the horizon, A, can be identified with the left Rindler wedge, and that doesn't seem right to me. It seems to me that A should be identified with the region behind the Rindler horizon, which is *not* the left Rindler wedge; it's the causal future of the origin (i.e., of the point at which the Rindler horizon and Rindler antihorizon cross). Am I missing something, or is this a real flaw in the argument?