Only a small minority of the 75 percent of the Greek population who own a mobile phone believe there are times and places when good manners dictate their telephones should be deactivated. How many of us have been disturbed while watching a movie by the sound of a telephone ringing, a nuisance now common in theaters, university lecture halls, schools and even churches. As a result, now that the majority of Greeks have become proud owners of a mobile telephone, ways are being sought to rid ourselves of unwanted noise by creating «mobile-free zones» by means of GSM jammers, appliances that block mobile telephone signals by emitting signals of the same frequency. Although illegal, individuals and businesses are recognizing the need for them; they are also being used for security purposes. The use of jammers is governed by a European Union directive (99/5/EC). According to an official statement by the European Commission, member states cannot obstruct the use of mobile phones through the use of jammers. However, according to officials at the National Commission for Telecommunications and Post (EETT), the European Commission is considering a change to the legislative framework to allow their use. The jamming debate emerged after the French government’s decision to allow them to be installed in the country’s cinemas. Elsewhere, jammers have been installed as far afield as India’s Parliament House, Italian universities, theaters and cinemas in Japan, Canada, China and Russia, and hotels and restaurants in Scotland. In Greece, they are used in only a few places, such as at the Athens Concert Hall. Apostolos Foukis, honorary president of the Panhellenic Union of Cinema Owners, told Kathimerini that 95 percent of all movie houses are still plagued by the persistent ringing of mobile phones. Jammers are available over the Internet, at prices ranging from 300 to 2,500 euros. Security is also a serious incentive for installing jammers, as bombs are often activated by telephone. Jammers were widely used, therefore, during the Olympic Games.