When this was all still secret, I was at a conference in a conversation with some emanations security people and they were remarking on the internal case of a n

When this was all still secret, I was at a conference in a conversation with some emanations security people and they were remarking on the internal case of a new Mac server at the time that had round perforations in it, likely to make the aluminum frame cheaper in raw materials, but they were noting how this would impede some of the interception capabilities.