Black Hole Complementarity Frustrates Detecting Duplication

Even if information were duplicated across the black hole horizon, the laws of quantum mechanics and gravity ensure any attempt to witness the duplication is always frustrated: to collect the information in Hawking radiation takes so long that by the time an observer jumps in, the infallen copy has already hit the singularity, so no one can ever measure both copies—analogous to the uncertainty principle for position and momentum.