Louis Theroux's documentary Law and Disorder in Johannesburg touches on the topic of private security. As someone with no experience of such situations I found

Louis Theroux's documentary Law and Disorder in Johannesburg touches on the topic of private security. As someone with no experience of such situations I found this fascinating: http://www.youtube.com/watch?v=KZJ1w9-Umcw http://www.youtube.com/watch?v=KZJ1w9-Umcw One section shows a situation similar to that which you described, in which the private security guards beat a suspected criminal to discourage repeat behaviour. Interestingly, the most brutal of the private security guards later falls foul of a mob of citizens, and must be protected/arrested by the real police (there's a chance I'm confusing this with another Theroux documentary).