"Jamming communications systems--including GPS, radio and wireless systems--poses a threat to law enforcement and public safety across the country. The likelihood of jamming exacerbating a disaster grows each day as illegal jammers become more prevalent in the United States. Jammers interfere with public safety communications and may leave responders without vital communications and critical situational awareness. Proliferation of jamming devices may delay emergency response times, escalate hazardous situations, facilitate illicit activities, or result in loss of life. For more information and to see examples of jammers, please see the 2015 U.S. Department of Homeland Security (DHS) -- Federal Communications Commission Bulletin: Cellular, GPS, Wi-Fi and other Signal Jammers. The DHS Science and Technology Directorate (S&T) is resolute in making first responders safer and more aware of jamming and its potential impact to their communications, safety and ability to execute their mission. S&T is combatting jamming threats by evaluating the threat, developing and testing mitigation technologies, working with public safety agencies to update training procedures, and raising awareness of jamming threats and characteristics."
Department of Homeland Security: https://www.dhs.gov