Unless one is a trained primatologist a person really shouldn't be keeping primates, they will not be provided for in a responsible manner. The enrichment they require is quite extensive, when a male goes through sexual maturation it can become rather aggressive and it really doesn't matter how large the animal is it can become rather difficult to care for, the females will have different health needs at sexual maturation that one may not be aware of and that can sometimes become life threatening. Then of course there are the various health issues that come with the species that one may not be aware of, it's important to understand that and to not put not only yourself but others at risk, to cause an outbreak of something viral simply by ones own ignorance is unacceptable especially because of ones desire to own an exotic pet.
The rights of the animal to live in it's own habitat in relative freedom should trump our desire to keep it in an unhealthy and unsafe captivity however if that isn't reason enough then the right to protect the public from individuals from those illequipped to care for the species should trump the right for them to own the animal.
https://www.thestar.com/news/gta/ar...asons-you-should-never-keep-a-monkey-as-a-pet
For those that are interested Darwin the Ikea Monkey has now found his way to a sanctuary in Ontario and donations can be made online.
https://www.indiegogo.com/projects/294104
https://www.storybookfarmprimatesanctuary.com/