While originally intended to "underscore the dilemmas and concerns that people would face if they relied too heavily on the new communications infrastructure," Stand Alone Complex eventually came to represent a phenomenon where unrelated, yet very similar actions of individuals create a seemingly concerted effort.
A Stand Alone Complex can be compared to the emergent copycat behavior that often occurs after incidents such as serial murders or terrorist attacks. An incident catches the public's attention and certain types of people "get on the bandwagon", so to speak. It is particularly apparent when the incident appears to be the result of well-known political or religious beliefs, but it can also occur in response to intense media attention. For example, a mere fire, no matter the number of deaths, is just a garden variety tragedy. However, if the right kind of people begin to believe it was arson, caused by deliberate action, the threat that more arsons will be committed increases drastically.
What separates the Stand Alone Complex from normal copycat behavior is that the originator of the copied action is not even a real person, but merely a rumored figure that commits said action. Even without instruction or leadership a certain type of person will spring into action to imitate the rumored action and move toward the same goal even if only subconsciously. The result is an epidemic of copied behavior-with no originator. One could say that the Stand Alone Complex is mass hysteria-with purpose.
This is not unlike the concepts of memes (refer to the conversation between the major and the Puppet Master in the manga) and second-order simulacra. It also has ties to social theory, as illustrated in the work of Frederic Jameson and Masachi Osawa.
It has been posited that the choice, by the writers of Ghost In The Shell: Stand Alone Complex, to use J.D. Salinger's short story, The Laughing Man as a key element in the story, was itself an example of second-order simulacra; the use of a story that could already be considered an example of second-order simulacra, by its popularity overshadowing the popularity of its original, The Man Who Laughs. This creates yet another example of the concept, by banking on the popularity of the show, the character, and the emblem used to represent The Laughing Man, supplanting the story as the Laughing Man by popularity alone.