On 31 May 2009, at 11:28, Olivier MJ Crepin-Leblond wrote:

"Andy Davidson" <andy@nosignal.org> wrote:

...

IP networks can't function properly (or at least, as intended) when consumers of addresses start using addresses that are already assigned to others already.

We shall see this be a problem for networks who ignore this warning as the last v4 /8s start to be assigned.

Actually who is mandated to act as a policeman when this happens? Is it IANA? Is it the RIRs? Is it informal routing agreements outside the realm of these organizations?

Nobody - just as nobody can guarantee reach-ability. Andy