Forward-looking infrared

[2] Thermal imaging cameras such as the Raytheon AN/AAQ-26 are used in a variety of applications, including naval vessels, fixed-wing aircraft, helicopters, armored fighting vehicles, and military-grade smartphones.

The cost of thermal imaging equipment in general has fallen dramatically after inexpensive portable and fixed infrared detectors and systems based on microelectromechanical technology were designed and manufactured for commercial, industrial, and military application.

In 2001, the United States Supreme Court decided in Kyllo v. United States that performing surveillance of private property (ostensibly to detect high emission grow lights used in clandestine cannabis farming) using thermal imaging cameras without a search warrant by law enforcement violates the Fourth Amendment's protection from unreasonable searches and seizures.

[11] In the 2004 R. v. Tessling judgment,[12] the Supreme Court of Canada determined that the use of airborne FLIR in surveillance by police was permitted without requiring a search warrant.

Ian Binnie distinguished the Canadian law with respect to the Kyllo judgment, by agreeing with the Kyllo minority that public officials should not have to avert their senses or their equipment from detecting emissions in the public domain such as excessive heat, traces of smoke, suspicious odors, odorless gases, airborne particulates, or radioactive emissions, any of which could identify hazards to the community.

[14] A FLIR Talon multi-sensor camera system equipped with an infrared laser pointer (which is invisible to casual observers) for illumination purposes was used to gather data at night.

[15] The American Civil Liberties Union raised concerns over the fact that new surveillance technology is implemented without judicial guidance and public discussion.