In the 1920s, the term balkanization was used to describe the formation of small groups of people who shared similar beliefs and ideas and might be hostile to groups with antithetical ideas. Balkanization tends to divide groups of people instead of uniting them. This well-observed trait has expressed itself on the Internet too, leading to the creation of the term "cyber balkanization," in the late 1980s. The idea that the Internet is not the global community once envisioned, but instead can become a place where people purposefully avoid information is at the heart of this concept.

Cyber balkanization may refer to the practice of some people to affirm ideas that they have online and forcefully disregard any that are contrary to those they agree with.

Cyber balkanization doesn’t necessarily mean that groups formed are hostile to others. When listserves first became popular, a Jane Austen listserve probably didn’t spend much time discussing other writers, especially modern novelists. The focus of the group would have been to evaluate the works of Austen, and pass on information about new Austen productions or writing about her. Such listserves are subject limited, but they doesn't necessarily imply that those belonging resented people belonging to other groups.

More controversially themed groups, either in listserves, chats, blogs, or other Internet manifestations, might specifically attempt to project hatred or anger about other groups, however, and to keep the group from gathering information that could be contradictory. They also may discourage outsiders from joining. Political groups of all persuasions have a tendency to practice this, and they may only reference the work of people disagreeing with them in order to criticize it. Such groups can have tendencies toward repeating stories that aren’t true or that are told from a specific slant, and this can whip up resentment toward others instead of a desire to understand things from an objective perspective.

Similarly, many religious online groups practice forms of cyber balkanization, especially when these religions are rigidly constructed. Many of these groups aren’t interested in exploring the way their faith differs from other faiths and can respond hostilely if commonly held opinions are attacked or even mildly questioned. The goal is not to learn, but to affirm beliefs and to eliminate information that doesn’t serve affirmation goals.

To an extent, Internet access that is controlled by certain restrictive countries may be a form of cyber balkanization, too. This is similar to countries that don’t operate a free press. Concept of keeping people “out of the know” and making sure the world is interpreted by strict standards is not global and permits few questions. Many people with freedom of speech and press choose to isolate themselves in this way, however, to avoid information that conflicts with their belief, and they often belong to narrowly constructed interest groups only.

This behavior is in direct contrast to the theory that the Internet is a place where people are constantly exposed to new ideas. Instead, people may go online to affirm the ideas they already have and to try to squelch any ideas they disagree with. This isn’t always the case, of course, and there are plenty of people in search of knowledge and understanding who don’t belong to restrictive groups and are open to learning more. It’s perhaps best explained that this form of isolation can and does occur, but there are others who take full advantage of the “global community” path the Internet offers, as well.