On Sun, Apr 2, 2017 at 11:48 AM, mok-kong shen <mok-kong.shen@t-online.de> wrote:

I wrote previously in a follow-up to a thread that I vaguely remember to have read that in US a permission is needed for Farady shielding of rooms, whereupon a few readers doubted its correctness. I have just succeeded to again find the source:

A. Stanoyevitch, Discrete Structures with Contemporary Applications. CRC Press, 2011. On p.301 there is:

Buildings can be fitted using a special insulation procedure that protects against tempest devices, but any company or individual in the US who has this insulation must first obtain a license from the federal Government.

I'd think that, unless intended not to for whatever reasons both legit and unbenownst, which is prefectly fine, a poster should reference first, a link to such publication. and that such publication should include links to any applicable laws or promulgated regulations in forwardance of their claims. Otherwise they might seem shady bunk and intentional chilling effect upon freemarket development of tempest applications.