I registered NetworkDefense.Ninja this past week. I kept looking at the new domains and debating the worth of registering anything. I decided the .Ninja domains are affordable. At $15, I’m basically throwing away 3 drinks at a bar.
I tried extremely generic domains like security.ninja, InfoSec.ninja, etc. they were all taken. I found ActiveDirectory.ninja and Domino.Ninja open, but I’m neither an Active Directory domain admin nor a Lotus Domino admin.