It should be against the law for people to keep these animals.
You never know when they will do something like this.
After all, they are wild animals.
An article about this attack in Scientific American says that, pound for pound, a chimpanzee is five times stronger than a human. An adult male also has massive canine teeth. They are violent and aggressive animals and impossible for a human to control fully. The owner of this animal should be in jail.
Male chimps are notorious for attacking humans, especially male humans because they see them as rivals. Chimps are cute when they are young but as the males grow into puberty they become vicious.