Before the Battle of Trebia, Hannibal wanted to set up an ambush for the Romans. He gathered 200 of his best troops together, and told them (a) that they were squad leaders; (b) they each should pick 10 of their friends to form their individual squads; and (c) the plan of attack.
A modern person might ask: "Well, why didn't he just gather ~ 2000 soldiers together and communicate the plan of attack directly? That must be better than passing a battle plan via a game of telephone".
The simple answer is that, before electronics and without a purpose-built theater, you really could only speak, directly, with about 200 people at once, because that's as far as the unaided voice can carry.
Many inventions and societal changes over the course of the past 2,000 years have accelerated the flow of information. Printing presses, movable type, widespread literacy -- I doubt that many of Hannibal's troops could read! -- postal systems which eventually spread across the globe, telegraphs, telephones, fax machines...
Each of these increased the speed, range, and coverage of communication to a varying degree, and each had a profound impact related to the scope of that change.
Humanity is only about a decade or so into a world where J. Random Person has the potential, through viral spread, to communicate with the full extent of their social graph, and to find like-minded actors.
Compared to before, this is a massive change, and if you weren't old enough to understand The World Before The Internet, it's hard to grasp just how massive of a change this has been.
Our cultural and legal mechanisms simply haven't caught up yet, nor have they adapted to the new evolutionary tempo.