String theory provides an example of the kind of apparent inconsistenc
y that the principle of black hole complementarity deals with. To a fr
eely infalling observer a string falling through a black hole horizon
appears to be a Planck size object. To an outside observer the string
and all the information it carries begin to spread as the string appro
aches the horizon. In a time of order the ''information retention time
'' it fills the entire area of the horizon.