SIB

The Superhuman Investigation Bureau, or SIB, is a domestic intelligence and security service of the United States and an auxiliary federal law enforcement agency. The SIB grew out of the special branch of the military police that was established in conjunction with the US' super soldier development programs during WWII.
There are a number of critics of the SIB who view the bureau as an example of government overreach and its actions as often infringing upon the constitutional rights of those with superhuman abilities. Officially, there is a very clear line drawn that the SIB has no jurisdiction in cases involving no superhumans, and the SIB is not allowed to infringe on constitutional rights more than is "immediately and obviously necessary for the preservation of the lives and liberties of a significant number of American citizens." In practice, though, there has been some criticism that these guidelines are circumvented or entirely ignored in a great number of cases.
The SIB is responsible for the compilation and publishing of the power-ranking of superhumans, both domestically and abroad. 
The SIB maintains close relations with the Defenders. While not technically members of the Bureau, the members of the Defenders active roster through the years have consistently made a point of involving the Bureau and maintaining good relations, with the Bureau has reciprocated.

Type

Government, Law Enforcement