It was a usual feature and often the principle element of early prison uniforms. The visual aspect of bare feet is therefore used to contrast the conventional appearance as footwear is regarded an obligatory clothing feature in urbanized cultures. Besides the indicatory aspect going in bare feet restricts the freedom of action in many situations. A barefooted person is therefore disadvantaged opposite a shod person in many practical respects. This aspect is often used to exercise physical control over individuals in captivity.
No going back after finding out separating children from their families at the border was Kelly's idea and that they did a trial secret run of it for over a year. I have no doubt one day we are going to hear stories of sexually abused children when this is all done.