The Followers of the Cupric Band were a group that existed within Vulcan society.
Their mistaken belief and logic led them to the belief that rejected the concept of intelligence flourishing within species with a non-copper based blood. They were noted as being active at the time when Vulcan began to first formulate its first contact protocols.
In 2373, during the Virogen Crisis, the Followers of the Cupric Band were one of the many terrorist elements on Vulcan that were mentioned by Srell. (TOS novel: Avenger)