olemus
(1) riigiasutus vastuluure ja sisejulgeoleku ülesannetega, kontekstist ja õigusruumist sõltuvas tähenduses; näiteks FBI, FSB, Kaitsepolitseiamet, NSA, DCSA (http://www.dss.mil/),
MI5 (https://www.mi5.gov.uk/)
= a state agency with counter-intelligence and internal security functions, in a context- and legal-space-dependent sense
https://en.wikipedia.org/wiki/Security_agency
https://en.wikipedia.org/wiki/Secret_police
https://en.wikipedia.org/wiki/Security_agency#List_of_security_agencies
https://www.google.com/maps/d/viewer?mid=18Ea8dzSXVx-5gqaHSQekIeiAig8&msa=0&ll=47.80684619105971%2C12.304687999999942&spn=143.185831%2C10.898438&z=2
https://en.wikipedia.org/wiki/Estonian_Internal_Security_Service

(2) turvafirma
https://en.wikipedia.org/wiki/Security_company
https://www.securitydegreehub.com/most-powerful-private-security-companies-in-the-world/
Eestis:
https://turvamees.ee/turvaettevotted/