Beginning in the late 1980's, marijuana growers began to cultivate their plants in indoor greenhouses; in response, the Drug Enforcement Agency initiated the use of infrared equipment to identify areas where disproportionate heat sources would reveal the use of grow lights. In Penny-Feeney, the Court ruled that infrared emissions were waste heat and, as garbage, could be searched without impunity, and that infrared emissions were similar to the smell that is detected by a trained narcotics dog without a warrant. The author concludes, following an analysis of the issues and case authority, that a warrant should be required to use infrared photography to determine what is occurring within a private dwelling or attached garage. 94 notes