Why does America's tax man need stealth phone tracking devices?
The Internal Revenue Service has its own criminal investigation unit, with 2500 special agents busting tax frauds and other financial crimes, including drug and terrorism-related crimes. And according to a report from The Guardian citing documents from a Freedom of Information Act request, the IRS is the 13th US government agency that owns Stingray devices — cell phone tower simulators that can track people by scraping their phone metadata:
The 2009 IRS/Harris Corp invoice is mostly redacted under section B(4) of the Freedom of Information Act, which is intended to protect trade secrets and privileged information. However, an invoice from 2012, which is also partially redacted, reports that the agency spent $US65,652 on upgrading a Stingray II to a HailStorm, a more powerful version of the same device, as well as $US6,000 on training from Harris Corporation.
Most documented Stingray use stems from court orders called PEN registers, which allow law enforcement to "track and trace" someone's location, not the content of their phone conversations — but Stingrays can also be used as wiretapping devices.
We don't know how the IRS is using these surveillance tools. While these documents only show that it bought them, not when or where it uses them, it's not clear if Stingrays get used on a daily basis or trotted out once a year for big money laundering busts.