Internal security is especially relevant for multi-user systems; it allows each user of the system to have private files that the other users can not tamper with or read.
en.wikipedia.org The main responsibilities are internal security, human rights and freedoms, suppression and detection of crime, and protection of public order.
en.wikipedia.org It was further organized into sections covering political control, censorship, public records, prison camps, internal security troops, physical security, counterespionage, and foreign intelligence.
en.wikipedia.org It consists of three branches: general purpose forces, border defense forces, and internal security forces.
en.wikipedia.org Additional missions include assistance in safeguarding internal security, conducting disaster relief operations and participating in international peacekeeping operations.
en.wikipedia.org