Before social media, everyone even in the same school or town was mostly anonymous; all were going about their days roughly oblivious to others' dealings unless they personally encountered them. As a solution to this lack of visibility, people reported their individual complaints about others up a chain of command, to cops and a justice bureaucracy that executed standardized procedure to decide if and how to punish transgressions.
In today's world, everyone is on social media 25/8/375, and thus the dealings of each person can be made rapidly known to everyone if they are at all noteworthy. Thus, what's happened is that rather than sending reports of undesired behavior UP a VERTICAL hierarchy, it's instead transmitted HORIZONTALLY - making the majority of society directly aware of it, so they can deal with the offender how they please.
This is how technology facilitated herd justice, and undermined the legal process entirely. Today at present, vertical hierarchy of law enforcement/justice and social media facilitated mobocracy are two competing systems of crowd behavioral control operating in parallel and without control by a common actor.
