In 2168, the Federation starship Horizon visited the Iotian homeworld. During its survey mission, member of the Horizon crew caused cultural contamination, who were at the time in the beginning states of industrialization, when they left behind a number of technical manuals for items such as radio sets, but most damning was a book, Chicago Mobs of the Twenties (referred to as "The Book"), which was discovered by the natives. The highly imitative Iotians remodeled their entire society based on "The Book," thinking it was the model for a perfect society; Iotians treated The Book with religious devotion and tolerated no disrespect against it.
In 2268, the USS Enterprise visited the star system and discovered the extent of the contamination. After negotiations with several bosses on the surface, Captain Kirk was able to unite the bosses in a unified syndicate with the Federation acting as the supreme authority, which the bosses had to answer to. After returning to the ship, Doctor Leonard McCoy discovered he had left behind his communicator on the planet; Kirk, Spock and McCoy all worried that the Iotians would discover transtator technology and make significant advances in a short time. (TOS: "A Piece of the Action")
- Cirl the Knife
- Krako, Jojo
- Jailbreakers, The
- Okmyx, Bela
- List of unnamed Iotians
According to Star Trek: Deep Space Nine Companion, the original idea for celebrating Star Trek's 30th anniversary in Star Trek: Deep Space Nine was to have Benjamin Sisko and his crew return to Sigma Iotia to find the Iotians imitating the original series crew. It would have been a tongue-in-cheek reference to the 'typical' Star Trek fan. The idea was dropped in favor of what became "Trials and Tribble-ations".
According to The Worlds of the Federation, the Iotians made use of the inner workings of McCoy's communicator to learn transtator-based Federation technology. By the time a next starship arrived to the planet, the Iotians had built a Federation starbase-like installation in orbit and were all wearing Starfleet uniforms. By the 24th century, the planet had become a Federation protectorate with a rating of E+ on the Richter Scale Of Cultures and, though it was not quarantined, required all personnel to be cleared through an orbital customs facility before visiting the surface.