Closed shell syndrome is a disease/phenomenon in the Ghost in the Shell universe:
Progressive scientific achievements have created a world where technology permeates every aspect of human existence. The human beast, however, is very adaptable and individuals learn to master the computer dominated environment.
The concept of the closed shell syndrome takes the combination of hackers' ethics and escapists' addiction to the next level.
People (children) who mastered technology but fail to achieve balance within their individual and social selves, roam the net and others' brain with an intense thirst for information.
(This is the logical extension of teenagers constantly yakking on cellphones and the 3 years old neighbour's kid fixing your computer. The world goes on.)
To prevent them from misusing their power and causing damage, they are voluntarily or involuntarily prevented from accessing the net (their 'shells' become 'closed), and their abilities are channeled into constructing and deconstructing network barriers.
(This is the logical extension of systematically dumbing down young ones through the conditioning of schooling systems, making up diseases such as ADD (Attention Deficit Disorder), and drugging them with drugs such as Ritalin. Dangerous agents have to be prevented.)
In contrast, those who achieve mastery of themselves as well as computer technology become dangerous to established power structures and power holders.
(The Laughing Man, a real-time hacker, would be a representative of those who have achieved such mastery.)
The Ghost in the Shell world is not only a world of progressive technology; it is also a world of progressive social manipulation.
The human beast adapts to this as well, however, this is infinitely more dangerous to the entrenched system: technology specialists can be harnessed with relative ease - social generalists cannot be.
(Representatives of social generalists would be Gouda and Aramaki, Motoko and Kuze.)
In this case, the disease corresponding to the closed shell syndrome (or ADD) has been made up a long time ago: it is called 'adolescence'.