That said, I could see glueing a panel to block them as a visual to remind people that those ports are off, but not as a primary blocking device. More than likely its done via security policy.
So, whether or not you believe that it is a useful solution, it certainly did happen. As for alternatives to gluing, I assume that was time related: filling in a port is certainly faster than opening thousands of machines to give them a physical port-ectomy.
Because it was more of a reminder for stupidity. "Oh, look there is glue in there, that's right we not supposed to stick random USB devices in there". If the machine is on their desk, yes, they could plug in a PCI device that has an USB thing on it and still connect. But by that point they are really going out of their way, they are opening the case and such, and it will be very hard to maintain the idea that it was just a stupid mistake.
It also really is not trivial to chip off most types of even general-purpose epoxy with your finger on a flat surface, let alone a tiny USB port which your finger doesn't fit in. If the epoxy was selected with some level of care, it may be very, very time consuming, or nearly impossible to remove, even with the right tools.
No matter what, it's a helpful measure in addition to every other way you can also disable a USB port.
I have no reason to believe the person I worked with would make it up. There would just be no point in it.
> Its trivial to disable USB for a mass storage (or all devices)
Except there are hundreds of different kinds of devices, and you tasked with quickly "doing something to fix the problem". Do you have time to go and dig through different types of BIOS menus or open the cases to all of the machines. Or is it easier to get epoxy plungers and send an army of people from desk to desk. Normal epoxy is a pretty decent electrical insulator (some board or components used to even be dipped in epoxy to protect from environmental damage or tempering).
> I suspect you've never managed a non-trivial network before,
No, but I was selling a solution with one in it. And $40k was making a decent size cut in the profit margin.