It's easier than you think to "capture" selected chunks of the RF spectrum. DOD, etc, have had this capability for decades, civilians have had scanners and broa

It's easier than you think to "capture" selected chunks of the RF spectrum. DOD, etc, have had this capability for decades, civilians have had scanners and broadband radios for decades. Amateurs can record entire HF bands and decode multiple CW and other signals in real time with modern receivers and computing power.