The 364 inmates across five prisons cracked the software on their JPay tablets to increase their balances, an Idaho Department of Correction investigation found earlier this month.

Up to 364 inmates exploited a vulnerability in JPay tablets – which were given to prisoners for email, music and games – to improperly increase their account balances, officials said.

In April last year, the Florida Department of Corrections struck a deal with JPay. The private company, spearheading a push to sell profit-driven multimedia tablets to incarcerated people across ...

The tablets, made by prominent prison vendor JPay, give inmates the ability to use email, listen to music and transfer money, among other basic computing functions, but charge fees for some services.

For JPay or any other provider offering tablets, a person’s credit balance is most likely stored on the tablet rather than being transmitted on JPay’s infrastructure to a centralized server.