Well, i don't know if you guys have discussed this man in a bit, but the circumstances that lead to his "rage" is at least memorable, to say.
Feng Guohui - Life -
After Feng's birth his parents thought he was a girl, but when he was 10 years old they discovered that he was apparently neither a boy nor a girl and brought him to a doctor for examination. Much to his parents grief the physician came to the conclusion that Feng was intersexual, and from that point on he was the subject of gossip and ridicule by his neighbours, who claimed that his condition was god's retribution for his ancestors' sins.
His humiliations increased at the age of 14, due to his feminine appearance, even after the onset of puperty, and at the age of 18 he was dragged by some of his peers into a shed, where they stripped him naked and molested him. Although he took care to guard himself from further assaults he was repeatedly sexually abused by his peers, who raped him anally and ejaculated into his face, while holding his hands and feet. Since they threatend him not to tell anyone, and because he wasn't a woman he dared not to entrust anyone with his mistreatment.
To escape his tormentors he eventually left his home and sought employment as a temporary worker at the Yangjiang forestry management, though his intersexuality was soon discovered by others, and he became again the subject of speculation and mockery.
Feng eventually decided to visit a doctor in Guangzhou, who told him that he could surgically transform him into a man. Since the surgery was expensive Feng began to save money, and was finally able to afford it at the age of 21, after his parents supported him with their savings. To the joy of his parents and himself Feng was changed into a man after six operations, but the taunts by other people still did not cease. They ridiculed him by saying that he had picked up a dog's genitals, suspected that he was a homosexual, or engaged in bestiality, and generally avoided him like a plague.
At the time of the murders he worked as a forest ranger for the Luoqin forest management (罗琴林场) near Baisha (白沙镇).
- Murders -
On April 23, 1997 at about 4 p.m. the 25-year-old asked a carpenter in a nearby village to repair a wooden box for him and afterwards went to drink some tea, but soon came across a group of chatting men and women. Irate, because he was suspecting that they were talking about him, he grabbed a long knife from a wall, approached the group, and while yelling "I will kill you! I will kill you!" (杀掉你们,杀掉你们) began stabbing them. He killed three women aged 81, 59 and 27, as well as two 4-year-old boys, and fatally wounded another boy aged 5.
Feng also injured an 8-year-old girl, discarded his knife and then fled into the nearby woods, but was arrested by police 28 hours later while preparing to commit suicide. He was brought to the Yangjiang public security bureau where he was interrogated, under tears confessed to the murders, and demanded a swift death, stating that he had been alive long enough under the given circumstances (我已经这样活够了!).
Sources: this and this