L.A. County's GPS Ankle Bracelets for Criminals Don't Work Very Well

So those ankle bracelets that are supposed to monitor L.A. County criminals? Yeah, they're not working very well.
In fact, a quarter of them are busted, according to a county audit obtained by the L.A. Times.
The devices, manufactured at taxpayer expense by Sentinel Offender Services, have also given trouble to the state's parole department.
GPS ankle bracelets started becoming popular when the state began using them to monitor sex offenders who were out on parole. L.A. County Sheriff Lee Baca and other California sheriffs have started using them to help monitor probationers.
But according to the L.A. County audit, many of the batteries in the devices are faulty, and the trackers generate too many false alarms to be reliable.
In a letter to the county, Sentinel protested that county probation officers were using the devices wrong and that problems were due to "felons who had failed to follow directions," the Times writes.