the portrait weighs 1.5 tonnes and is generally replaced by a spare when it is vandalised. in 1989, three dissidents, including yu dongyue, attacked the portrait with eggs during the tiananmen square protests of 1989. yu was sent to prison and was not released until 17 years later in 2006. on may 12, 2007 the portrait of mao caught fire. a 35-year-old unemployed man from urumqi was arrested for the incident. about 15% of the portrait was damaged, and had to be repaired later. on april 5, 2010, a protester threw ink in a plastic bottle and hit a wall near the portrait. he was then arrested.