In the Babylon Five universe, the Psi Corps is powerful Earthgov agency responsbile for controlling human telepaths. Telepathically gifted children coereced to join (their alternatives are dangerous suppression drugs or jail) and are raised a indoctrinated by the corp.
Some telepaths later discover the true nature of the core and escape through use of the various underground railroads. These rogue telepaths are hunted down by the Psi Cops, a nasty group including the infamous Bester.