There's some interesting names and reasons here.
A little bit behind mine: It was actually supposed to be ModernKnight87 (my typical name) but someone had ModernKnight87 when I signed up for xbox live, so I used ModernNite87 instead.
Back in the medieval days knights wore shinning armor and traveled around by horse back. To me the definition of a knight this day and age is a Army/Marine Soldier. They carry large amounts of weight and gear in their assault packs/ruck sacks. Instead of a horse, the choice of travel is vehicle (typically a Bradley, LAV, HUMVEE, Stryker, or MRAP), in my case it was the M1 Abrams Main Battle Tank (Which was my original job) or Stryker (when I got stationed in Alaska, there was no M1A1's there, so we rolled in Strykers, and I went from being a tanker to infantry, doing the same exact thing every infantryman does, but without the title. The MOS was the only thing that separated me from 11B, was that I was still a 19K, but did an 11B job.)
So hopefully that wasn't too confusing, and perhaps a good way to look at things.