I don't think that the recent (unwelcome) publicity to which Blackwater USA has been subjected bears much comment. Some things speak for themselves, and it's not as though the rest of us didn't figure out 5 years ago that privatizing national defense to a series of completely unaccountable, secretive companies is questionable. I do, however, think that too little attention has been paid to the fact that Blackwater's founder and principal has strong ties to a number of psychotic Christian fringe groups. Similarly ignored is the fact that Blackwater is only one of a dozen such companies operating in Iraq, and it's actually less shady and deeply involved than some unknown places like Aegis.
Rather than speak at length making really obvious points about accountability, secrecy, and morality, I'll simply say that I find this subject fascinating and it's amazing how pervasive and shady the industry is. I had the good fortune of taking a graduate class taught by the former President of Liberia. It was not a good class, but god how I loved talking to this man about post-colonial Africa's near-constant state of war and flux. To hear him tell it, the stability of most West and Sub-Saharan African regimes had more to do with making sufficient monthly payments to Sandline and EO than indigenous military capabilities or domestic unrest. If you find this as intriguing as I do, I heartily recommend all of the following:
The Whores of War by Wilfred Burchette & Derek Roebuck (1977). It's hard to find, but a well-stocked college or public library should be able to find it for you. It's a detailed account of how mercenaries descended on Angola like flies on garbage in 1975, killing, raping, and generally acting like you'd expect society's rejects to act when given guns, brown liquor, and carte blanche.
Shadow Company (film, 2006) is a somewhat-uneven look at the history of mercenaries in the late 20th/early 21st. While it spends a lot of time on Iraq, it also contains some great history including interviews with EO personnel who intervened in Sierra Leone a few years ago.
Private Warriors by Silverstein and Burton-Rose is a brief but substantive look at the growth of the PMC industry in the last two decades.
Former Sandline chief Tim Spicer has written a fairly self-serving autobiography that is interesting less for its factual content than for its depiction of the mindset and worldview of the kind of people who do this for a living.
Lastly but not leastly, the indispensable (if somewhat sensationally-titled) 800-page reference volume The World's Most Dangerous Places by Robert Pelton, possibly my favorite living non-fiction author. You'll not find a better or more thorough run-down of who's involved where than through the work of Pelton and his contributors. Aside from being funny and extremely well-written, the depth of research and information is incredible. I wait for his books with baited breath (new edition next May!) but I'm not alone; the CIA and State Department regularly rely on Pelton and DP, which often contain far better intelligence about local conditions than the government can patch together. How does Pelton do it? First-hand reporting. Going into nasty places. You know, actual conflict journalism, not sitting behind a desk reading Pentagon press releases. I also spend far too much time at Pelton's website. Check out his new book about the use of PMCs in Iraq entitled License to Kill. I have not yet found the time to read it, but his track record suggests it will be terrific.