We're jamming

The NTIA is evaluating technologies for jamming contraband cell phones in prisons. The first question that comes to my mind is why are the prisons so incompetent that they can't prevent a cell phone from being smuggled? Really, is it that hard to blast all prisoners and visitors with a huge electromagnetic pulse? Phone fried, prisoner colon fried, problem solved. If you're lucky, you might even be able to kill two birds with one stone. And why aren't the prisoners being monitored more closely? If I have to constantly monitor my employees to make sure they're actually working, I assume the prison warden needs to constantly watch the prisoners to make sure that they're not up to no good. The prison system is essentially a free source of incarcerated labor. The prisoners should be constantly working and thus under constant supervision. The incarceration system is borken if they can't even keep the prisoners busy enough to not have opportunities to use their contraband cell phones.

Even so, I'm curious as to what solutions will be presented. I can monitor company e-mail and company phones to prevent employees from wasting time and misusing company resources. But they still have those wretched cell phones. If I can just jam them, I could prevent those personal calls from interfering with the productivity. Maybe then I could get them to do some actual work.