Do successful anarchist societies exist? Are there any examples?
There are no large scale anarchistic societies in the modern world, and none have been successfully maintained for more than a period of a few months. The only example I have found that is similar to an anarchist society is the walled city of Kowloon in the late 19th and 20th centuries which was situated in Hong Kong. It was formally owned by Britain after being leased to the country by China in 1898 but no formal governance was set up. Even within this city a local leadership was set up by gangs and criminal networks in order to maintain a modicum of order, but it was an accidentally anarchist society in that there were no formal laws or governmental structure. It was eventually evacuated and demolished in 1994.