This isn’t the first time the Netherlands has had to deal with an outage, albeit not for the same reasons — this one was under police control. A cellular network outage in August 2018 knocked out connections to 450 ankle monitors, forcing a similar scramble.

The wearables are frequently helpful for police by giving them a way to keep tabs on suspects and criminals without having to jail them or place officers nearby. This failure underscores a central problem, though: the monitors are highly dependent on reliable connectivity and software, and even a temporary glitch could put public safety at risk.