It seems everywhere I go in Thailand there are security guards. I realize that there are several companies but my question is who actually runs these companies. Is it the military, police or the mafia? I was also curious on how the security system works? I have heard that the guards get paid a pittance. From what I have seen some are well dressed and paying attention while others are sleeping.

Who do you think is the best/reliable security company?

Sorry , Just could not stop my self

Since most of theft are done by the security guard assigned to protect the property, then I assume is run by ex police

There's normal companies do so, search this one G4S as an example is worldwide but available here under contractual basis