Perhaps there is better wisdom out there on correct metrics
for these values. From my limited viewpoint, the only way
to recover the space is a voluntary return, based on the
original allocation policies.
There must be some mechanism implemented whereby address space will return
to the IANA after a specified period of time unless otherwise requested by
the prefix holder. Otherwise what will happen is that this 60% (or some
other large percentage when the figures finally settle) of the 192/8 address
space will effectively be lost from the internet with no real means of
retrieving it. A system like this without any garbage collection mechanism
is eventually going to fill up with defunct allocations and the cruft of
years past -- something which is not an option when dealing with limited
address space.
as a technological means to protect a networks internal
stability, is presumptious and rude at best and legally
indefensable at worst.
How are the InterNIC coping with the new domain name charging scheme? If
this were successful, a similar scheme might be considered for address
prefixes. The legal consequences are similar if not quite the same, and
one is really no more rude or presumptious than the other.
Nick