It is a very simple concept and allows for a wide range of freedom in creating identities. As many people have experienced, MUDs and other communication rooms are extremely addictive. This is potentially the most unintended consequence of MUDs. The addictiveness can create problems in other areas of life such as face-to face interpersonal interaction. Just like video games, smoking, and many other addictions, MUDs have the power to capture the user's attention and entertain it hours on end.
People make a good deal of their sense of communication through nonverbal cues.
For instance, someone can say they are happy, but people would have a hard time believing that if the person's nonverbal behavior did not agree. The most obvious detriment to CMC is that there is very little presence of nonverbal cues, unless teleconferencing is involved. Even then, the cues can be distorted or hidden, which changes the communication. This argument assumes that if users were not in the virtual arenas, they would still be on the Internet. Computers were traditionally made and purchased as a machine to help in areas of education and business.