I've done some business with Blackwater and worked with and for other similar firms.  I think, like the WW I Vets, most of the contracted employees of these firms would have to be seriously hoodwinked into taking up arms against the US Govt. as in an overthrow.  From what I saw, most were ex-military types who needed work and their skill sets matched what the companies had contracted to provide.  The work is often extremely hazardous, but no more so than what the military was paying them much less to do.  A lot of these companies are just shells until a contract comes along, then they start to hire to fill the contract requirements.  Much like a construction company.  Sometimes the companies have very little to offer in the way of resources and protections for their employees.  Several have been criticized for throwing contracted employees into Iraq without proper equipment or support.  That, I belive.  

I can swear there ain't no heaven but I pray there ain't no hell. _ Blood Sweat & Tears