Organized crime, also known as criminal organizations, are endeavors of crime run by a group of criminals. These endeavors are usually run for the purpose of earning a monetary profit, but may also include political motivations.
On Earth, the mob was an influential criminal organization during the 20th century. As humanity moved out into the stars, the influence of the mob was felt, as a book detailing the history of the Chicago mobs came into the possession of the people of Sigma Iotia II, who changed their society to match that of 1920s Chicago. (TOS episode: "A Piece of the Action")
In the 2250s of an alternate reality, organized crime was active in Russia on Earth and operated extensively in the online realm. The teenaged Pavel Chekov became a legend in the Russian online community as a white-knight hacker who crippled the operations of online scam artists. Chekov was known by a Russian screen name which translated as "MisterCleanUp". No one, not even the hackers employed by Russian organized crime, ever identified MisterCleanUp with Chekov. (TOS - Starfleet Academy novel: The Gemini Agent)
The Orion Syndicate was a powerful criminal organization that was active on an interstellar scale. Humanity first encountered the Syndicate in the mid-22nd century, and the syndicate was still active in the 24th century. (ENT episode: "Borderland" and DS9 episode: "Honor Among Thieves")