Let's say I encode all the information in some book in a light beam. Then I put a black hole in the way of the beam. Mass and information of the black hole increase as the beam plunges in the black hole. But what if the black hole is moving very fast parallel to the beam? In this case the rest mass of the black hole may increase very little as the beam goes into the black hole. There must be some mechanism that prevents us to dump information into a black hole without increasing its mass by a sufficient amount. So what might the mechanism be in this case?