GE miniguns are awesome, I love to have one, just to have one...
unfortunatelyits extremely hard to find one for sale andnext to impossible to afford to buy one even if you did, not tomention the outrageous cost of feeding it, a very good friend of mine has a full auto M-11(among a number of other machine guns) and that things is bad enough at ripping through ammo and the last I knew he was paying $1.25/round for ammo for his .50 machine gun...
those guns are fun, but a little too costly to feed for me

its not suprising to see the law enforcement/military with a setup like that though, however I've seen some pretty impressive civilian setups too, in fact thers any number of videos out that are neat to watch(knob creek in particular)