Freedom of information is often restricted by political, economic and other barriers. In some totalitarian countries, there is a persistent dissemination of false or distorted information because the media are controlled by governments who tolerate no opposition or criticism. In some democratic countries, the main information media are in the hands of powerful press magnates who impose their political views within the press organs under their control and leave neither room nor opportunity for the expression of a different line of thought. Probably the most serious restrictions of a legal character arise from such concepts as "official secrets", "classified information" and "national security". The State obviously has a right to withhold information affecting national defence from the public domain, but such rights are abused when they extend to cover information of a political character, or in the technical and industrial spheres and - worst of all - public opinion. The vagueness of these restrictions make them all the more insidious. Access to news sources is a particularly thorny issue. Governments which do not restrict information in other ways may refuse to grant visas, restrict journalists' movements, place limitations on those whom newsmen may contact, withdraw accreditation of journalists or expel them from the country. There are very often discrepancies between the treatment of national journalists and foreign correspondents.
Publishers, editors, and reporters unpopular with totalitarian regimes may be assassinated, or confined as political prisoners, where they may be subjected to torture. In the last five years, such events have occurred in Latin America, Southeast Asia, Africa and the Middle East. In western Europe, personnel associated with clandestine broadcasting of information to eastern Europe have been murdered.