I built it when I was with the CIA, to use to amplify brainwaves. The mental signatures of mutants differ from humans and so our resident telepath used the machine to find other mutants in an effort to build forces to prevent a very explosive disaster. If a human were to use Cerebro, it may cause harm though - overload, in a sense. There is a great deal of psychic feedback that occurs when using Cerebro that only telepaths can handle.