> (About #12, WTF? Weird!)
There is a fairly boring explanation to that. Similar to public IPv4 exhaustion, RFC1918-style private IPv4 addresses can easily be exhausted in a big private network as well. If you have noticed, MS has actually run out of RFC1918, and uses RFC6598 (a.k.a. 100.64.0.0/10) network in Azure for their "classic" segment. 100.64.0.0/10 was not supposed to be used as RFC1918-style general-purpose private IP space, but rather as a local side of a CGN pool. But then again, if you squint a bit, well... it's still private, so will never be advertised into the Internet, so it's fair game to use it if you run out of RFC1918, right?
Some people choose to squint even further, and declare anything that is not advertised into public BGP as a fair game. I've seen a big ISP "borrowing" 44.0.0.0/8 (amateur radio AX.25) subnet to deploy video segment of their huge "triple-play" network. 33/8 (US DoD) is also popular as "borrowed" private space, 1/8 was fairly popular until it actually became real public address space handed to APNIC (oops!). Now we have an example of using 25/8 like that as well.