Restrictions on the availability of national information to foreign media include: government secrecy; government control of information (both official data and propaganda); the expulsion of foreign correspondents and refusal of entry to others; and confiscation of articles, film, photographs, [etc]. Such restrictions hide existing injustices, inequality, exploitation and repression by keeping them closed to international scrutiny. They may encourage espionage and subversive activities or lack of cooperation and international tension. Most governments feel that they should be able to refuse imported programmes. Some use this position to censor TV and radio broadcasting.
Restriction of the movement of technical information may be used as a means of handicapping the productivity of other nations and as such is a form of techno-nationalism.