Read Bruce's comment "No barrier other than.. - bruce January 2, 2001 04:14:45".

I think that we have to be careful about the way that we interpret these equations. We have to keep in mind from whose perspective the results are given. We can't always trust what a remote observer will see while observing objects traveling at relativistic velocities. The observations are limited by the medium connecting observer and object. So the distant observer is not necessarily well informed.

The local observer near the event horizon would have more accurate information on what was happening. His neighborhood might be traveling near the speed of light and if the gravitational gradients were gentle enough he might not even be aware of the fact. One has to be very careful about approaching gravitational holes. You could be caught before realizing it.

However, even if you were so close that even light could not escape to infinity, it still might be possible to communicate across the event horizon using a network of relay stations. It would be necessary to step up the carrier wave periodically to compensate for the gravitational redshift.