Go to the UNESCO World Press Freedom Day website.
UNESCO promotes freedom of expression and freedom of the press as a basic human right. It advocates the basic human right of freedom of expression, enshrined in the Universal Declaration of Human Rights, and its corollary, press freedom. Indeed, since its creation in 1945, UNESCO has been called upon to “promote the free flow of ideas by word and image”.
Check out the Wikipedia site for World Press Freedom Day for more information on the history of the event.