GPS is great. Before handheld receivers became widespread, how did we ever find small boxes of random crap in the woods? Stalkers were among the first to see the technology's potential, using it to track the movements of ex-girlfriends by sticking modified cell phones beneath their vehicles, but the state of California thinks that GPS is ready to enter a new market: the hood.

San Bernardino county wants to start tagging gangbangers with GPS transponders. County commissioners have applied to the state to be part of a pilot program that would monitor all offenders who are released from jail after serving time for gang-related activities.

The program, which the county has started implementing on its own, is an innovative attempt to tackle the problem of gang violence, but it builds on similar California initiatives already underway. Last year, for instance, California voters enacted Jessica's Law, which forced all sex offenders to live more than 2,000 feet away from schools and parks. The law also require that all felony sex offenders submit to GPS-based electronic monitoring—for the rest of their lives. That's right, the bracelets need to stay on even after sentences are served and parole is over.

GPS has found a home in prison systems across the country, which love the devices for their ability to ease overcrowding and to enforce parole conditions. As long ago as 2002, such programs were becoming popular and even received support from the ACLU, which likes them because the devices make it easier for less-violent criminals to get out of jail and work a job.

Such systems generally rely on private companies that handle the monitoring of the GPS signals, which are transmitted by a small tracking device worn on the belt. A smaller wristwatch-type anklet is also worn by the prisoner at all times and cannot be removed without sending an alarm. Texas uses both active and passive systems, which are passed out based on risk. Parolees with higher risk factors get the active model, which allows for real-time tracking, while everyone else gets a passive version that downloads its data at the end of each day through a base station in the user's home.

Such systems have revolutionized the parole system, making it much simpler to enforce compliance. The Texas system, for instance, makes monitoring simple: "When TDCJ district parole officer Taylor Goodlett looks at his laptop computer screen each morning, he normally sees a lot of little green dots. The dots tell him exactly where a high-risk offender on his caseload had gone the day before and that he was, in fact, authorized to travel to those locations. Red dots, on the other hand, alert him that the offender might have gone astray."

The system also displays the speed at which people are moving, meaning that parole officers can also find out if people were doing 95mph down side streets the night before.

San Bernardino hopes that such technology will help the county to keep people from slipping back into gang activity by restricting movement into known gang-controlled areas. For those who want to go straight, the knowledge that Big Brother is always watching should provide additional incentive.