Very strange sounds like some daft EU regulation. Fan guards and covers for electrical parts? I've built tower pc's for years and I've yet to chop a finger off with a pc fan, or electrocute myself either.
On the other hand I don't see the other big pc makers pulling their tower computers so I would have expected Apple to do what is required to comply with this.
Barry, reread my post: it is an international rule of the International Electrotechnical Commission http://www.iec.ch
with the following list of national affiliations http://www.iec.ch/dyn/www/f?p=103:5:0
and the revised standard also in practice applies to any new product introduced in the US as of March 1, 2013, due to the de facto need for UL certification.
I suspect that the problem is that Apple did not plan on keeping the current MacPro model around for so long, so either
(a) its design predates those new standards, or
(b) the proposed standard was known back when the current Mac Pro was designed (about six years ago), but back then, Apple expected to have a new, compliant model out before the compliance deadline of March 1, 2013.