ICE is now tracking nearly 54,000 immigrants via ankle monitors

Shift in monitoring methods has led to revenue boost for Geo Group, a private prison firm, that also makes the device

The US is tracking nearly 54,000 immigrants through GPS-enabled ankle monitors as part of a US Immigration and Customs Enforcement (ICE) electronic surveillance program, according to private prison corporation The Geo Group. Early last year, just 17,000 immigrants were wearing the devices..

The Geo Group owns BI Inc, the company that runs ICE's intensive supervision appearance program (ISAP), and reported the numbers in its earnings call on Thursday.