[amluto]

When my internal network connects, via any non-NATed means, to a vendor’s internal network, there is a chance that my addresses conflict with theirs. If the vendors have even a few tens of clients, this risk is quite high.

[enkid]

This is especially true because people tend to use the same private addresses over and over. How many devices are 192.168.1.1 vs. 192.168.52.123 ?