If it is written down, it's called "libel" whereas if it's spoken, it's called "slander." Defamation law attempts to balance the freedom of speech and open exchange of ideas without giving someone permission to run around spreading lies about another that may harm his or her reputation, ability to earn a living, etc.
The Nobel Peace Prize 1984 was awarded to Desmond Mpilo Tutu "for his role as a unifying leader figure in the non-violent campaign to resolve the problem of apartheid in South Africa.
