Libraries in Hong Kong are forced to take sensitive books off shelves. The topic, and others sensitive to central government in Beijing, are deemed too "harmful" to share with the public.
These include books detailing the bloody massacre of peaceful demonstrators in Tiananmen Square in 1989, which the autocratic Communist Party does not want to acknowledge. Hong Kong was long a largely autonomous conurbation in China, but in recent years the government has taken control of the political system and judiciary, and significantly restricted freedom of expression.