Assemblies and methods for securing a fiber optic network cassette assembly are provided. A typical secure cassette assembly includes a cabinet adapted to be locked on both a front and rear side of the cabinet. Internally, a plurality of cassettes are placed on a cassette tray adapted to slide back and forth within the cabinet. Insert pins are placed into holes on the cassettes locking into the cassette tray. A limiter is placed inside the cabinet that prevents the cassette tray from sliding when engaged. If one of the cassettes is forcibly removed, the insert pin will shear the fiber internal to the cassette and destroy the cassette, thereby disabling the network and typically alerting a network administrator or designated individual.