The United Pirate Clans are a loose organization of pirates and raiders that plague the Pocket Universe. They are equipped with spaceships with Hyperdrive. They have been around as far back as Year 1500 of the New Shi'ar Calendar. These pirates are mostly Shi'ar, but also include members of other races including Humans and Orks.
The Pirate Clans have been a serious thorn in the side of legitimate interplanetary governments like the New Shi'ar Imperium for thousands of years.