The medium is that which spreads the message. Since the mediums operate differently from each other, only certain types of messages can be transmitted over each one.
Before written systems, a message could only be spread by word. The message could be stopped by disappearing the person speaking.
Before print media, messages could only be written down by a scribe or learned person, and the message could only be read by another scribe or learned person. Or messages could only be passed in the form of images. Those messages could be stopped simply by burning/destroying the written/etched copy that existed.
Before the telegraph, messages could only be delivered in person, on foot or on horseback or by ship, limiting its rate of spread to those transportation speeds. Those messages could be stopped by intercepting the delivery, or controlling the territorial borders.
Before radio and telephone communications, transmitted messages could only be read by telegraphists. The messages could be stopped as long as there was no telegraphist at the time of message transmission, or if the telegraphist lied about the message.
Before televised media, only messages in the form of voice or text could be transmitted far distances, so only voice or text was consumed. The information bandwidth was extremely small, although fast.
Before internet media, only audio, video, or text could be transmitted. The information bandwidth increased with video, but these high information channels were only controlled by media elites and governments.
With internet media, internet isn't a message you consume, internet is something you participate in. The instant participation of the global population in a single activity is something altogether new that is a step-change in what has been available, and no prior medium could have prepared us for this age. The old media elites still want to control what messages are dispersed, but the new medium doesn't cede that control easily.
Before written systems, a message could only be spread by word. The message could be stopped by disappearing the person speaking.
Before print media, messages could only be written down by a scribe or learned person, and the message could only be read by another scribe or learned person. Or messages could only be passed in the form of images. Those messages could be stopped simply by burning/destroying the written/etched copy that existed.
Before the telegraph, messages could only be delivered in person, on foot or on horseback or by ship, limiting its rate of spread to those transportation speeds. Those messages could be stopped by intercepting the delivery, or controlling the territorial borders.
Before radio and telephone communications, transmitted messages could only be read by telegraphists. The messages could be stopped as long as there was no telegraphist at the time of message transmission, or if the telegraphist lied about the message.
Before televised media, only messages in the form of voice or text could be transmitted far distances, so only voice or text was consumed. The information bandwidth was extremely small, although fast.
Before internet media, only audio, video, or text could be transmitted. The information bandwidth increased with video, but these high information channels were only controlled by media elites and governments.
With internet media, internet isn't a message you consume, internet is something you participate in. The instant participation of the global population in a single activity is something altogether new that is a step-change in what has been available, and no prior medium could have prepared us for this age. The old media elites still want to control what messages are dispersed, but the new medium doesn't cede that control easily.