They're far more than just a galaxy. It's more like several for some of the empires. [Well, very few really.]

Pirates are sorta like that! They do rob banks, and ambush United ships to steal their goods. [And kill all the members on the ship, but she'll leave that part out.] Oh, United is the government of the human galactic empire by the way. [Let's not talk about them.] Some pirates even have feuds against one another. There's also a band of pirate lords, you could say they're second in command in a way, and above them is the pirate king!