If you’re a customer with Telstra, you quite probably noticed that their mobile services dropped out for a while there yesterday. What you might not have noticed (unless you are living under some very specific conditions), is that this outage also saw a bunch of ankle monitors used to track people within the correctional system lose connectivity.

As the ABC is reportingSouth Australia Correctional Services was unable to track around 750 of the electronic ankle bracelets for a period of two hours yesterday during the Telstra outage.

They’re also reporting that the similar blackouts on May 4 heavily impacted the bracelets in Queensland and the Northern Territory. In the NT, 85 bracelets were affected, with some of the issues taking “up to four days” to resolve.

A spokesperson for Queensland Corrective Services told the ABC that 299 of the devices in Queensland were affected, but that the wearers have no way of telling when the device is on or off, and that they have contingency plans for when they go out (such as locking them indoors).

The ankle monitors are used primarily to ensure that the criminals being tracked stay in or out of specific areas and are obeying any time-specific curfews that have been applied to them.

Telstra has attributed the outage to a software fault.

Image: Getty Images / Bastiaan Slabbers