Internal security officers have knowledge of the premises they are protecting. A security officer in charge of state internal security affairs knows the state's boundaries and its weak points, inside and out. He is therefore required to liase with the officers in charge of external security to reach a properly informed decision on the best way to protect the country.
Internal security officers dictate who or what goes into the premises and what doesn't. Prison officers, for example, are responsible for the security within the prison walls and dictate who enters the prison premises according to the nature of business. Individuals undergo a thorough security check including body frisks to ensure they do not carry any object that may undermine the security of the prisons.
Loop holes in a country or state's border offer convenient channels for traffickers and smugglers to operate. This is a major problem for internal security officers in any state. Traffickers and smugglers greatly affect a country or state's economic status. Smuggled goods are cheaper in any market since they do not incur taxes upon importation. Drug trafficking also affects a country or state's economy as it affects the work force of the nation, mainly the youth. Internal security officers therefore strive day and night to solve this issue. In Mexico, a major problem facing military and police agencies concerned with internal affairs is drug trafficking.
Corrupt and underhand dealings are a characteristic of almost any field of work. The internal security department is no exception. Some internal security officers believe their wages do not match their expenditure for daily basic needs and therefore seek alternative income-generating activities. Internal security officers may take bribes to allow smuggling of goods along borders or even sell out information on internal security measures about their state.