Neither of the names are PR gold. 'Blackwater' is the plumber's term for sewage. 'Xe' sounds alien or like a B-movie villain accent: "We have xe plans, nothing will prevent xe final solution now!"

The genius behind 'Xe' is that some people will say 'zee', others will say 'ecks-ee'. If someone hears something bad about the organization by mouth, they won't know what to type into Google to read about it, and even if they do know how to spell it they'll get hits about a noble gas and a currency exchange site.