One of my students in Istanbul introduced me to this. Up to the mid-1990s, one could go into an upmarket pet emporium in Istanbul and find a bored chimpanzee in a cramped cage, waiting for some rich fool to buy him and dress him in designer nonsense.
At that point, the laws were brought into line with those of most of Europe. It became illegal to keep several species, including chimpanzees, as pets in order to get rid of the demand that had led to them being dragged out of their homes. Hence, there was suddenly a population of chimpanzees in Istanbul that needed housing and care of a reasonable standard.
This was Darıca zoo  which took on this expensive and time-consuming role. Hearing about this from my student, we organised a school trip to Darıca. Here, we found a large collection of apes of various sizes, ages and social proclivities.
The ones that made the biggest impression on most people (including me) were the very young ones, recently taken from the wild. They seemed to have adjusted well to the idea of social interaction with humans and probably missed their erstwhile owners. It was our job to get in with these infants and play with them. This was something of a stopgap as they would inevitably be joining breeding populations of chimpanzees in zoos around the world at some stage. In the meantime, we were their parents/playmates.
They were lovely. As long as one remembered to take glasses and jewellery off before contact, they were gentle, funny and endearing. Having no option, they readily accepted the opportunities presented by us and played, vocalised and cuddled like socially advanced babies.
I hope they enjoyed their subsequent lives. I hope we helped in some way.