This was one of the layers. It absolutely did not necessitate gathering up every single one at once.
"The man who made the devices said there’s little someone inside could actually do with a hacked Securebook. They’d need to fashion a USB port, be able to install another operating system, and get access to a docking station, said Jeremy Schwartz, Justice Tech president. Even when the devices are docked, they’re not connected to the wider internet. "
Sure, they can commit crimes with it.
But prisons obviously don't care about their charges committing crimes or they would take serious measures to prevent violence.
So, the outcome might be harsh, but it is NOT overreacting to promptly deal with secure devices becoming easily rooted.