Encryption doesn't stop "sending frequencies through our head...." but that's a topic for another thread. LOL.
I've been an electronics hobbyist all my life, starting at an early age. Like father like son applies. My dad was an electronics hobbyist and exposed me to lots of tech stuff while growing up. I became his first assistant on every electronics project or home repair project, including a few car repairs. My interest in all things radio has nothing to do with public safety. And whenever things did not work when they should, I always want to dive in and fix it.
When I was about 4, my dad had a (now antique) electric train setup around the Christmas tree. He explained how it is powered by electricity and he explained it as best he could at a level that a 4 year old could understand. He warned me to always be careful with electricity because it can be your enemy and electric shock can be dangerous and be like getting "bit" by it. I remember asking if the electrons were going to jump out and bite me. LOL. On another occasion I remember asking dad if electricity cared what color wires they go through, referring to the color of the insulation on the wires. LOL.
As an electronics hobbyist while growing up, I got interested in all things radio. At 9 years old in 1970, I built a RadioShack Knight Kit 5-tube AM table radio kit. I brought it into school (3rd grade) and demoed it there.
For the many eBayers who were watching and those bidding on my recently finished auction of item number 321051134387, an unassembled Knight-Kit KG-311 5 tube AM radio, here's another chance - sort of.
www.worthpoint.com
At 10 years old in 1971, I helped dad build a Heathkit 14" color TV for the family. That TV gave us 13 years of trouble free service. Over the years our family earned a reputation for having the oldest TV sets in town because my dad and I kept repairing them. My first scanner was a Heathkit GR-1132 VHF-Lo/Hi/UHF 8 channel crystal scanner which I built in 1977 during my freshman year in high school. I previously was using a portable multiband tuneable radio to listen to local VHF public safety stuff in my area and a few 2m ham repeaters. I've had many scanners since then and too many to count. I was getting interested in Amateur Radio too but I didn't get my ham license until 1983 (Novice in 1983, upgraded to Tech in 1984).
In 1978, I built a Heathkit H8 personal computer and the H9 video terminal for dad as my intro to digital electronics and personal computers. I was the envy of my high school's math department for a couple of years until they got a couple of early personal computers. LOL. One thing I quickly discovered with the H8 and H9 was they were mighty potent sources of RFI and completely trashed my scanner reception. They weren't designed to be RF-quiet at all. The FCC at the time was also dealing with many interference complaints from digital electronics and were working on Part 15 regulations for computers and other digital devices. The FCC Part 15 Subpart J rules first came into effect in 1979. This is now Subpart B in Part 15. I recall the Apple II and the RadioShack TRS80 were notorious for being RF noise generators back then.
I studied Electrical Engineering in college and today I am an Electromagnetic Interference/Compatibility (EMI/EMC) Engineer. FCC Part 15 and the international equivalents guides my work. Dealing with being a victim of RFI from the family's personal computer system while growing up comes full circle, LOL. The hobby interest in electronics and ham radio definitely played a part.