Artemis Section is a black operations unit of the US government which answers only to the President himself. It is responsible for finding and gathering intelligence about 'people of interest'. They are also tasked with the Black Ops of snatching the target individual. During the books Aftershock and Deadlock, it is they who are responsible for finding any information to do with Otto Malpense. They are also tasked with retrieving him.
Artemis Section have a huge intelligence database that covers almost every individual on the planet: except Otto, Raven, Wing and all their friends. To be a 'flagged' individual on the Artemis Section database means that the said individual is a notorious criminal that must be caught at all costs. They are prepared to go to almost any length to retrieve a "flagged" individual.