The Cambodian government has arrested Cambodia's most prominent human rights activist, Kem Sokha, on charges of criminal defamation. The charges relate to a banner displayed in a Human Rights Day rally, which according to the government
labeled [Cambodian Prime Minister] Hun Sen as a "communist" and a "traitor who has sold away (Cambodian) land to Vietnam."
(This seems to relate to a recent treaty stablising Cambodia's border with Vietnam, which has upset Cambodian nationalists; whether Kem Sokha was actually responsible for the banner is unclear.)
Article 41 of the Cambodian Constitution guarantees freedom of expression. Unfortunately, this "freedom" no longer seems to include the freedom to criticise the government. In recent months, at least four critics of the government have been arrested on criminal defamantion charges, and others have been forced to flee the country. Ironically, this had caused Kem Sokha to help establish an Alliance for Freedom of Expression in Cambodia to oppose the use of criminal laws to silence critics of the government. Unfortunately, now it seems that he'll be needing its assistance.