[Cryptography] Regulations of Tempest protections of buildings

[mok-kong shen]

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.

M. K. Shen