They were once of notable concern to the US government because they were often clustered around sensitive research and military installations, such as Los Alamos and Sandia National Laboratory, then Sandia base.
それらはかつては政府にとって心配であったが、なぜなら、ロスアラモス国立研究所(Los Alamos National Laboratory)やサンディア国立研究所のような、敏感な調査、軍事施設のまわりにしばしば群がらせられたから。