Odd that you ask this question as I was discussing this the other night.
There was a family in SC that owned a 5-year-old chimp. It was their pet, lived in the house, wore diapers, etc. They lived in a rural area that was mostly comprised of other family members. One night, the chimp got out of its cage and left the house. It stalked the bushes around the grandmother's house down the street. For some reason, it wanted to attack the grandmother. maybe it saw her as weak or something, who knows. Anyway, when she arrived home at night, it followed her inside and beat her. She took refuge under a futon and literally kept the thing at bay by hitting its arms with magazines when it tried to reach for her.
She could not reach the phone, and had been beaten up pretty badly, so she was stuck there for an entire 13 hours or something until the person who was feeding the monkey realized he had escaped.
The family decided to keep the monkey, despite it attacking the grandmother who spent two weeks in the hospital, and the grandmother never pressed charges. This never made media attention for some reason, I am not sure why.
The only reason I know about this is because I am friends with the cousin, who basically told the family he was going to come shoot the monkey himself if they did not put it down or send it to some sort of zoo. They finally did give it to some zoo, after like 3 months.
Talking to my friend, he says there is NO WAY any man could take a 3 foot chimp in a hand-to-hand fight. They are just too nimble.