Since its founding in 1988 by Magneto, the Brotherhood of Mutants has been known as a radical metahuman faction and has been designated as a terrorist organization. The active leadership has changed several times over the decades, with Mystique and others playing the prominent role; though through most of their existence Magneto remains active in the background if not as the primary leader. See +group Brotherhood on game for the current situation.
While there is often a primary team of members, the Brotherhood also includes some cells scattered around the world, as well as most recently calling Asteroid M in orbit around the Earth their home. While the most central members often hold some profile among mutantkind, remote members may be common criminals who got into petty theft or vandalism, or who have have conducted raids of government property or destroyed public buildings.
In the past few years the Brotherhood seems to have changed directions. The organization's primary focus remains mutant rights no matter where in the world they live, with the most dramatic change being that they are seeking to achieve these goals without resorting to the use of the terrorist or radical methods of the past.
At this time they have a truce with Xavier Institute for Higher Learning and the X-Men, and have worked with them on several missions. They hope to maintain their working relationship with other organizations around the world as they take this brave new approach toward their goals.