Honestly wondering if this was done deliberately by DOJ tech folks who weren’t on board with the cover-up.

I have heard of a gov employee keeping a usb cable in a locked cabinet because they thought it had leftover data after use.

(I’m guessing they misinterpreted a zero effort PowerPoint presentation)

Not actually an insane practice. There are compromised cables that look normal but have hidden storage to record data for later retrieval.

The problem isn’t that they were keeping a USB cable in a secured location for security covens, the problem was that they were doing so because they believed bits were left over in the copper itself and enough such that data would be recoverable. Like marbles through a tube.

I do hope the practice was due to your point and that the particular person was just naive, misinterpreting a presumably shitty PowerPoint.

I was assuming an imperfect narrator. The only person who knows why the cable was locked up was the one who locked it up.
That’s the opposite. Your protecting the cable from being manipulated. OP is talking about protecting the cable from being read.
Assuming that the cable hadn’t already been manipulated, in which case they were protecting it from being read.