Anti-Western sentiment in mainland China has been increasing since the early 1990s, particularly amongst the Chinese youth. Notable incidents which have resulted in a significant anti-Western backlash have included the 1999 NATO bombing of the Chinese embassy in Belgrade, the 2008 demonstrations during the Olympic torch relay and alleged Western media bias, especially in relation to the 2008 Tibetan unrest. Whilst available public opinion polls show that the Chinese hold generally favourable views towards the United States, there remains suspicion over the West's motives towards China stemming largely from historical experiences and specifically the 'century of humiliation'. These suspicions have been increased by the Chinese Communist Party's "Patriotic Education Campaign".