communication of restricted data about atomic weapons, an example --- @Vladimir It is indeed illegal with exceptions. Take a look, for example, at the US Code Title 42 Section 2274 prohibiting the communication of restricted data about atomic weapons. Restricted data means "...(y) The term "Restricted Data" means all data concerning (1) design, manufacture, or utilization of atomic weapons; (2) the production of special nuclear material; or (3) the use of special nuclear material in the production of energy, but shall not include data declassified or removed from the Restricted Data category pursuant to section 2162 of this title".

Source author: Scott Spence scott.a.spence@gmail.com