This weekend, the Charlotte Observer ran this article, entitled Charlotte Police Investigators Secretly Track Cellphones. The article concerns the use of so-called stingrays, also known as IMSI catchers or cell site simulators. They are machines that simulate cell towers and connect with the cellular telephones located nearby. Officers frequently use them to triangulate the location of a suspect – or more precisely, the location of a suspect’s phone. There’s a controversy about the legal status of these devices, which I’ll summarize in this post.