Those guys in the video look very much like Deputies dress (even thier patches are identically shaped) and as well they also look similar to
Army/Marine personnel. They really should not be dressing like that, they are even guys wearing padded vests (or what appears similar to a flak
jackets).
After much searching this is what I have found regarding private security companies:
B&P 7580.1. As used in this chapter, "director" means the Director of
Consumer Affairs, unless the context indicates otherwise.
B&P 7582.26.
...
(d) No licensee, or officer, director, partner, manager, or
employee of a licensee, shall use a title, or wear a uniform, or use
an insignia, or use an identification card, or make any statement
with the intent to give an impression that he or she is connected in
any way with the federal government, a state government, or any
political subdivision of a state government.
...
(f) No private patrol licensee or officer, director, partner,
manager, or employee of a private patrol licensee shall use or wear a
badge, except while engaged in guard or patrol work and while
wearing a distinctive uniform. A private patrol licensee or officer,
director, partner, manager, or employee of a private patrol licensee
wearing a distinctive uniform shall wear a patch on each shoulder of
his or her uniform that reads "private security" and that includes
the name of the private patrol company by which the person is
employed or for which the person is a representative and a badge or
cloth patch on the upper left breast of the uniform. All patches and
badges worn on a distinctive uniform shall be of a standard design
approved by the director and shall be clearly visible.
The director may assess a fine of two hundred fifty dollars ($250)
per violation of this subdivision.
...
(i) No private patrol operator licensee or officer, director,
partner, or manager of a private patrol operator licensee, or person
required to be registered as a security guard pursuant to this
chapter shall use or wear a baton or exposed firearm as authorized by
this chapter unless he or she is wearing a uniform which complies
with the requirements of Section 7582.27.
B&P 7582.27. (a) Any person referred to in subdivision (i) of Section
7582.26 who uses or wears a baton or exposed firearm as authorized
pursuant to this chapter shall wear a patch on each arm that reads
"private security" and that includes the name of the company by which
the person is employed or for which the person is a representative.
The patch shall be clearly visible at all times. The patches of a
private patrol operator licensee, or his or her employees or
representatives shall be of a standard design approved by the
director.
(b) The director may assess a fine of two hundred fifty dollars
($250) per violation of subdivision (a).
B&P 7582.28. (a) Any badge or cap insignia worn by a person who is a
licensee, officer, director, partner, manager, or employee of a
licensee shall be of a design approved by the director, and shall
bear on its face a distinctive word indicating the name of the
licensee and an employee number by which the person may be identified
by the licensee.
The provisions of this section shall not be construed to authorize
persons to wear badges who are prohibited by Section 7582.26 from
wearing badges.
(b) The director may assess a fine of two hundred fifty dollars
($250) per violation of subdivision (a).
B&P 7583.38. A city, county, or city and county may regulate the
uniforms and insignias worn by uniformed employees of a private
patrol operator and vehicles used by a private patrol operator to
make the uniforms and vehicles clearly distinguishable from the
uniforms worn by, and the vehicles used by, local regular law
enforcement officers.
*
CHAPTER 11.5. PRIVATE SECURITY SERVICES 
