The Bat-Signal is a fictional distress signal that light-up the Bat sign to call Batman and Robin when there's a crime happening or when James Gordon has a lead on a case. Gordon, Harvey Dent, Harvey Bullock, Hamilton Hill, and Barbara Gordon has access to the machine. Many spoofs of the machine are made in many shows.
- Brodkin, Jon (2012-07-19). "Internet Defense League creates "cat signal" to save Web from next SOPA". Ars Technica. http://arstechnica.com/tech-policy/2012/07/internet-defense-league-creates-cat-signal-to-save-web-from-next-sopa/. Retrieved 2012-08-26.