http://www.truth-out.org/beyond-wiki...ation-war66239
"... Under the United Nations, a convention was adopted which outlaws and criminalizes their activities. Additionally, Protocol I of the Geneva Conventions also contains a definition of mercenary. These non-state entities of the 21st century operate in extremely blurred situations, where the frontiers are difficult to separate. The new security industry of private companies moves large quantities of weapons and military equipment. It provides services for military operations, recruiting former military as civilians to carry out passive or defensive security.
However, these individuals cannot be considered civilians, given that they often carry and use weapons, interrogate prisoners, load bombs, drive military trucks and fulfill other essential military functions. Those who are armed can easily switch from a passive-defensive to an active-offensive role and can commit human rights violations and even destabilize governments. They cannot be considered soldiers or supporting militias under international humanitarian law, either, since they are not part of the army or in the armed forces chain of command, and often belong to a large number of different nationalities.
PMSC personnel cannot usually be considered to be mercenaries, for the definition of mercenaries as stipulated in the international conventions dealing with this issue does not generally apply to the personnel of PMSCs, which are legally operating in foreign countries under contracts of legally registered companies.
Private military and security companies operate in a legal vacuum: they pose a threat to civilians and to international human rights law..."

W's answer to U.S. unemployment. Ain't it great to be a PMSC personnel person.