The primary tool of phone phreakers was the “blue box”, a device that could emulate the tones used by the phone system. The design and construction of the blue boxes became just as big a part of the phreaking community as exploring the phone system itself. Ironically, the construction of blue boxes was originally made possible due to Bell Telephone’s publishing of technical service manuals, which described in great detail how the tone signaling system for its communications network operated. It was by studying this documentation and reverse-engineering the signaling system that phreakers were able to bend the system to their will.