Yes they are. You can read more about exactly why here and here, but the long and short of it is that .io is a geographic domain tied to the British Indian Ocean Territory, an archipelago in the Indian Ocean formerly known as the Chagos Islands.
In the 1970s the British government wanted a quiet, remote piece of territory in which to do the kinds of things governments like to do in remote territories. The Chagos Islands were deemed a sufficiently quiet and remote corner of the Empire, and the Chagossians who had been living there were evicted from their homes. The military installations built since on the islands have been implicated in all kinds of unpleasant business.
The .io domain can only exist because of the creation of the British Indian Ocean Territory - it's a direct acronym for the name of the administration.