Private security forces?

The more I read, the more I think that so-called "private security forces" may be ruling class death squads:

http://www.aljazeera.com/programmes/peopleandpower/2013/04/20134393022542771.html

The government of a nation-state has a monopoly on the use of physical force within its borders. Even the UN cannot enter without that government's permission. "Private security forces" which violate that mandate are criminals. They should be dealt with in a lawful manner, not by just killing them.