Folks -
A network that wants to be creative and utilize an address block that’s assigned to others
for their own internal purposes runs two distinct risks:
1. An address block that’s not utilized today may easily become publicly routed tomorrow
(either by the original address holder or by their assignee/successor) and it is not possible
to reliably predict whether your customers will need access to the resources that end up
on that address space.
2. If you should leak routes publicly for another's address space, there are organizations that
will object – and in the case US government networks, this can include some uncomfortable