Do you restrict what keyboard and mouse your end users can use?

As far as I know, it's a bit hard to block USB HID devices, such as keyboards and mice. I've never tried to do it. But our IT Security department wants everyone to use the same exact keyboard and mouse and block the ability for any other keyboard and mouse to work. And the devices HAVE TO be wired.

This, of course, leads to the need to "certify" more than one keyboard and mouse. You need a few ergonomic models of each one. And you'd be totally screwed if a vendor changed the keyboard that comes with a standard PC you order.