Sort of off topic, but I was cleaning out some files (real paper files) and came across a small one from my ham radio days (I was an avid ham operator until I got married around 1968.) The license classes have changed dramatically since I went through the novice-general-technician exams when I was 9 to 10 years old (got novice when I was 9, general shortly thereafter, but technician (the one I really wanted because back then that was the only one that allowed you to actually _talk_ over the air) was a royal pain because it had a pretty significant morse code requirement.)) I think 15 words per minute but I am not certain that was so long ago. In any case, in those days I was an "Allied Radio" fan (Chicago Illinois electronics supplier) for their "knight-kit" product line which was all I could afford at that age.
BTW I used to think 9 was pretty young, because these exams are/were written, although back then it required a visit to a local FCC office to take the thing. It required some pretty good math skills, and a significant amount of electronics knowledge. But that was right up my alley back then and I simply ate that sort of stuff up. But today, for fun, I was looking at current ham license classes and such, and ran across a five-year-old that has his ham license. I notice that they have dropped the morse code requirement around the world, but the electronics requirement is STILL pretty involved. Pretty amazing that a 5 year old could do this.
In any case, in my old file, I found something I suppose the FCC sent to me for historic reasons or something, a piece of paper saying that in 1942, ALL amateur radio licenses were suspended, because the Navy was concerned about radio frequency interference. I did not remember that and had never seen it mentioned. I guess WWII was a strange time in many different ways... It came with a really roughly typewritten note saying that the FCC can, upon orders from the military, suspect amateur service in time of war. I guess that copy was to show me what a real notice would look like...