In the early 1960s, twin brother grad students studying social psychology at Harvard embarked on a behavioral study to test the effect of positive reinforcement on young offenders. Robert and Kirk Gable theorized that by giving small rewards to youths who got onto the straight-and-narrow during their probationary period, authorities might cut recidivism rates.

The twins proposed the idea to their adviser, who just happened to be none other than clinical psychologist and famed LSD advocate Timothy Leary. Along with behaviorist B.F. Skinner, Leary signed off on the project hoping that, like his experiences with LSD, changing behavioral patterns could in effect transform the mind, and thus “improve the human condition”.

UCLA student wearing a tracking belt Robert Gable

The twins came up with a simple — and at the time fairly benign — solution. They would create a schedule for each of their subjects, and equip each of them with an electronic tracking beacon belt built from old military surplus radio equipment. If the youngsters showed up to their scheduled appointments on time, they were rewarded with modest prizes such as pizza parties, movie tickets, and free haircuts.

The Gables experimented with the belts in Cambridge, Massachusetts and Los Angeles, and while they encountered some mixed results, the short-term benefits showed that keeping “low-risk” juvenile offenders “tuned in, turned-on, and wired up” with radio tracking belts and the occasional free haircut worked better than keeping them locked in the hoosegow.

As time went on, the project and the technology evolved. Working in Los Angeles, Robert Gable came up with a way to use the belt to both send and receive signals; a series of vibrations gently reminded the belt wearer of an upcoming appointment or check-in phone call. But given the limited technology of the receivers, monitoring a large group of subjects literally required a dedicated FCC-licensed radio station. Though they had shown positive results, Gable eventually ran out of funding. The project was shelved — that is, until a New Mexico judge stumbled upon a Spider-Man comic strip.

In a 1977 comic strip, your favorite wall-crawling superhero was tagged with a radar tracking device by his arch nemesis the Kingpin for the purposes of “zeroing in” on Spidey whenever he wished. The Honorable Jack Love happened upon the comic, and had what he thought was a brilliant idea. Facing rising crime and overcrowded jails, why not go all comic book villain on low-level offenders and slap a tracker on them? It would keep nonviolent offenders from sucking up prison resources, while the court could charge the lawbreakers a tidy monitoring fee for the privilege.

As it turns out, both the criminal justice system and the free market loved the idea inspired by the Marvel universe’s biggest crime boss. Within months of pitching his idea to salesman and amateur engineer Mike Goss, the National Incarceration Monitoring and Control Services (NIMCOS) was born. Based on the work done by the Gable twins at Harvard, the new anklet tracker was smaller, more reliable, and used phone lines sending signals to a computer mainframe, eliminating the need for a network of dedicated radio stations.

While proponents of electronic monitoring say being on monitored house arrest beats sitting in jail (which, fair point), it’s the economic benefit that really launched the industry. Incarcerating an adult male can run anywhere between $50 to $150 per day, while electronic monitoring runs anywhere between $5 and $25. Many local governments use electronic monitoring as a profit center: while the service costs a few dollars a day, cities like Mountlake Terrace, Washington change offenders $140 a week for close to a 300 percent profit.

The Gables, for their part, were horrified. Yes, surveillance was always a part of the package, but it was a means to a much greater end. Their vision included a full suite of rehabilitative tools designed to replace prison sentences — to make offenders more productive members of society through positive reinforcement — not a for-profit, court-ordered babysitting shakedown. With technological innovations, the twins predicted their bracelets could transmit real-time health information to medical centers, incorporate an online-based incentive system, and even facilitate a “bluetooth AA” support network.

It seems like the Kingpin has the last laugh. More than 100,000 Americans are currently wearing ankle bracelets, most for those awaiting trial and/or as a condition of parole or probation. Ankle bracelets are also being used as a way to track asylum seekers, refugees, and undocumented workers, allowing state agencies to “keep an eye on them” from centralized monitoring stations. With a refugee crisis dominating the national conversation, and prison overpopulation still a problem, it seems the for-profit electronic monitoring industry, already a $6 billion a year industry, will continue to prosper.