Shaikhul-Islam, Ibn Taimiyyah , said that there are those from the people that backbite or listen to backbiting, and they do so to please the company they keep, with the awareness that the victim is likely to be innocent of some of the things that are uttered about him.
Often such offenders feel that if they were to attempt to end such conversation in a gathering, their presence might become unwelcome or burdensome. There are many methods and guises that are employed when one mentions another in a negative way. Under the pretense of being informative, one could say that it is not one's habit to mention others, except for the sake of relating another's condition to someone. Or one could state that by Allah, indeed so and so is one to be pitied, thereby showing superiority over one who is to be rejected. Another method might be to say that so-and-so is a good person; however, he has such and such qualities. Again, one is justified in revealing another's faults. One could also simply state that we should forget so-and-so, and make supplication for their forgiveness as well as our own, intending only to belittle the one that was mentioned. In reality, all these tactics are designed to try to deceive Allah (the Exalted) and to please the creation; and in reality, the many that follow these methods only serve to deceive themselves.
Then there are those that backbite to raise their own status. When they hear of someone's error, they employ words like, I had I prayed for so-and-so last night in my prayed, the news of their sin would not have reached my ears." Again, when a person states of another that he lacks understanding in a matter, the implication is personal superiority for the one that mentions the other's shortcoming.
There are also those that couple jealousy with backbiting the act of being critical or belittling to those that are praised in the company of others. Some people also backbite for the sake of humor, playfulness and lightheartedness. A person finds a certain amount of satisfaction from being appreciated for his story-telling abilities; speaking ill of someone in a humorous fashion adds flavor to a tale. Others engage in backbiting by showing surprise 'and amazement at another's actions.
How is it that someone could do such a thing? Yet others mention people and their actions with the pretense of sympathy for their actions or misfortunes. In reality, the one who backbites actually finds contentment and satisfaction at the mention of others and their misdeeds.
Another form of backbiting is relating some ones misfortune to their enemies, so that they, too, may find pleasure in putting them down. From these examples, one can surmise that backbiting pertains to a disease of the heart... May Allah save us from this most evil of actions and protect us from its temptations.