BTW one of the arguments I have heard against IG is that the "one way" penetrations through metal cabinets and raceways that are not bonded at both ends actually creates a choke that reduces the effectiveness of the IG. (similar to GECs)
IBM decided it was better to bond the hell out of everything. In the 60s we had single point grounding and we had to do a "baseplate ground" <continuity> check, lifting the single point ground and verifying that was the only path to ground.
After all the engineering changes were installed that "single point" was getting up to 20 or 30 additional grounding wires (added to fix problems) we had to remove to clear all paths to ground and sanity finaly won out. They stopped thinking star grounding was important. It was about that time that the IG dissapeared from the physical planning manual. In your typical PC you will have lots of DC to AC ground points once you start hooking up I/O.
