U.L. Paper

United Liberty Paper is a cover for a mysterious organization that has a huge amount of influence and authority in Liberty City. Almost no information is given through in-game content other than "They aren't the good guys, but work along side with the good guys" and they aren't the FIB. It is possible and highly likely that UL Paper is a cover for the United States Department of Homeland Security. The missions given all deal with terrorist activities, adding support to this. The organization cannot be the CIA or NSA, as the NSA and CIA are involved in sensitive, often secret national security operations that deal with intel gathering, not anti-terrorism operations. Since the DHS deals with stopping domestic terrorism and threats to US soil, it is the most logical identity of the mysterious UL Paper organization. Since the threat of terrorism in Liberty City was great and the public was under the impression the terrorist threat had passed, the UL Paper organization felt it necessary to breach protocol and contract outside help, in order to remain secretive and not cause a city wide panic.

Although they remain mysterious throughout the story, it becomes somewhat evident what their job is. All of the missions given by U.L. Paper have something to do with halting terrorist activity within Liberty City, which ultimately succeeds. The contact of U.L. Paper is a middle-aged man with spectacles, who had a military career prior to his employment in the UL Paper organization. He is curt and rude, but understanding of Niko, as they are both military men who served their respective countries. Through working for UL Paper, Niko ultimately gets the person he is looking for, Darko Brevic, delivered to him, courtesy of UL Paper (the locating of Brevic was presumably done by an intelligence agency, most likely the CIA, who work in conjunction with the DHS).