"I'm writing about SW, the shortwaves, covering the frequency spectrum between 3 and 30 megahertz. Those used by radio amateurs, CB language, aeronautical communications over long distances, Morse Code. Every moment, each of us is crossed by electromagnetic waves: from satellites that transmit weather information, gprs tracking systems, celestial objects far away from us thousands light years. And, among other, military transmissions in code. All things that have a direct impact on our lives in terms of means by which propagates the information; but whose final disclosure (or not know) has consequences on our destiny: to know whether or not the bad weather ahead, to know whether or not a war bombing in advance.Some sections of the frequency spectrum are reserved for certain types of transmissions, and some are free; so far, nothing particularly exciting. The political power grants the right to exploit the physical phenomenon of the frequencies for the "common good". It’s a political issue: citizens vote a government, the government appropriates certain radio frequencies because they have to be in the public interest and not only in the interest of a few (a government doing the interest of all and not just of a few is a statement to be verified, but we go off topic with this).Except that "sometimes" "someone" transmits illegally encrypted messages. To simplify things we'll call this one: Mysterious Issuer, MI. The MI send coded messages of different types on shortwaves: voice, in the case of the famous Number Stations; in the form of polytones, or sound sequences. Anyone (with a CB radio or connecting to radiotelescopes that make available to anyone who has an internet connection the shortwaves captured) can happen to run into this particular kind of transmissions. What are they? What do they mean? Mystery.Experts of cryptology believe that are secret communications: secret services of various countries send their message to undercover agents in enemy territory. Another possibility: they are rebels, guerrillas or terrorists who exchange informations. The special feature of an encrypted communication on shortwaves is that: it could be broadcast by everyone, but only those who have the decryption key can get to the meaning of information.During wars, riots and revolutions, broadcast codes on shortwaves multiply: difficult to locate, because they propagate quickly in the air without suffering from any obstacles, come from one side of the planet to the other very easily, reflected towards the Earth's surface due to the ionized layers in the atmosphere. Therefore, it is very difficult to be able to triangulate the signal to understand where is the place from which a MI, a Mysterious Issuer, is transmitting; and absolutely impossible to know the whereabouts of the LR, the Legitimate Receiver. Between MI and LR, there are all the others: those who listen to the frequencies, but do not know what it is: the Others Listeners, OL.If an OL picks up an encrypted transmission between a MI and a LR, we face with an interesting dilemma. If he translates encrypted communication of a terrorist group that is turning information to its agents for an attack, could save lives; if he founds out a military code coordinating actions on the ground, to put an end to an armed conflict between nations, would prefer not to disclose this information. When an OL picks up a code on shortwaves, he does not know who is sending it, does not know what it means, only his deciphering put him in the need to take a position in respect of it. In the moment in which the first sequence of sounds, transposed into numbers, becomes a possible word, everything changes: OL is deciphering itself, its position in respect to the situation that is emerging in front of him. In addition, we also consider the possibility that OL decipher wrongly the code: and takes a position respect to facts misinterpreted, but related with what he believes to have translated.Decipher a code takes time, the right tools, and attention. Selective perception helps us to move in a mass of information that bombs us every day by various MI: because often we think we know who is "producing" information, but we do not know really. Selective perception, unconsciously, directs our attention on that "we need" more than others: those that meet our interest, those that we think we can use to our advantage. Always supposing that our selective perception functions properly.On the other hand, we "produce" information, more or less in good faith that it can be interpreted for what we intended to say, but also for what we do not know that we said. Snap a picture, put it on the web: I would like to see all my friends the beautiful sunshine today. Someone who is not in the circle of my knowledge sees this photo, and decrypts another message: where I am at that time, or who is with me, if there are people in the photograph. We produce more information than we think.The amount of data produced every day has mind-boggling numbers. Every day, people uploads to Facebook more than 200 million of photographs; each month, on Youtube are seen 6,000,000,000 hours of video. Twitter, in October, 2013, had assets 232,000,000 (232 million) of active users. In 2005, humans have put on the web 150 billion of gigabites (150 exabytes); currently we have far exceeded the 1,500 exabytes. And this is a taste of the public sphere; if we consider the video information gathered by US drones in Afghanistan only in 2009, it would take 24 years to be viewed in full."