1. A method for outputting an alert indicating a functional state of a back-up video-broadcast system, the method comprising: a computing device receiving first closed-captioning data that corresponds to a first video-stream, wherein the first video-stream was generated by a primary video-broadcast system; the computing device receiving second closed-captioning data that corresponds to a second video-stream, wherein the second video-stream was generated by the back-up video-broadcast system; the computing device comparing the received first closed-captioning data and the received second closed-captioning data; based on the comparison, the computing device making a determination that the received first closed-captioning data and the received second closed-captioning data lack a threshold extent of similarity; and responsive to the determination that the received first closed-captioning data and the received second closed-captioning data lack the threshold extent of similarity, the computing device outputting an alert indicating that the back-up video-broadcast system is not functioning properly.