Nobody is really sure if it's conspiracies, aliens, or secret agents secretly communicating with each other from the four corners of the globe.
But whatever the cause, numbers stations have had people tuning in and talking about what the heck is going on for nearly 80 years.
As WWII ended short wave radios started to become commonplace in people's homes as a hobby. They were also used as something a little darker and much more mysterious: a way for unknown individuals to communicate and interact using a strange, vague code—numbers.
They normally consist of a female reading groups of numbers, sometimes letters or sound tones, in a monotone voice and without saying anything else. Intervals could consist of a few minutes to once a day, week, or month.
A common one, known as “The Lincolnshire Poacher” because it used the bars from the English folk song with the same name, showed up at the height of the Cold War in the mid 1970s.
It continued broadcasting until June 29, 2008 when it stopped unexpectedly and without another word. This one in particular was broadcast several times throughout the day, seven days a week.