国安部披露：某养殖场为防范竞争对手，私自网购并安装信号干扰器，全然不知此举将干扰民航飞行关键信号，危及民航安全

Group 1 - The article highlights the illegal installation of signal jammers by individuals and organizations near airports and railways, which poses a significant threat to civil aviation safety and disrupts public transportation operations [1][2]. - A specific case is reported where a breeding farm installed a signal jammer to prevent competitors from using drones, inadvertently interfering with critical aviation signals, leading to safety hazards for civil aviation [2][4]. - Another incident involved a car pawn shop that installed jammers to block GPS signals, which also affected high-speed rail and subway communications, prompting legal actions against the responsible parties [4][5]. Group 2 - The National Security Agency emphasizes that signal jammers are illegal and warns the public against their purchase and installation, urging citizens to report any suspicious activities [7][8].