This is the era of hyper-tech espionage, encrypted emails and mindboggling cryptography. But you can hear a very old-fashioned form of espionage on shortwave radio.It is 13:03 on a Tuesday in a cramped room with some fairly advanced radio equipment. What is suddenly heard on a shortwave receiving station is a 10-minute message in Morse code.There is a small community of aficionados who believe messages like this are a throwback to the era of Cold War espionage. They are the mysterious “numbers stations”.

read more: BBC News – The spooky world of the ‘numbers stations’.