This macaque monkey, named Dodo by his rescuers, was being used as a "dancing monkey" in Indonesia. It's estimated that people steal over 3,000 baby macaques from the Indonesian forest each year. They do this by wounding the mothers, forcing them to abandon their offspring.
Most baby macaques are sold to international pharmaceutical groups or universities, where they'll be used as research subjects. Others are sold in wildlife markets as pets, or to become dancing monkeys like Dodo.
Despite their name, "dancing monkeys" don't really dance. Instead they're forced to perform silly tricks like riding bikes, playing tiny instruments, or doing acrobatic tricks like walking on stilts. It's also pretty common for handlers to dress dancing monkeys in clothes, or make them wear masks made out of old doll heads.