Well in business terms the situation that you are describing is called a monopoly. A monopoly is when thee are only a few sellers but a large amount of buyers. Monopolies manipulate price and demand around them. Furthermore they also restrict the entry of new firms into the industry by using various methods. As they are monopoly they reap abnormal profits. Also they can set various prices that are unfair. They can carry this out because they are monopolies. So this is the reason why they are termed as being biased. Hope this answers the question.