No, it is not safe to just let him run around. He is presumably very scared and may pose a threat to whomever he encounters. Primates, and macaques especially, are very gregarious and social creatures. They need to be around others of the same species, or they can break down psychologically. Macaques are also known to carry the Herpes B simplex, which can be fatal to humans. This is not cool, this is not funny, and this poor primate needs to be caught soon and placed in a sanctuary with other macaques.