Today, lawyers must regard the practice of law as a business, inasmuch as they earn their livelihood from the practice of law. The marketplace for legal services is a competitive one; not only has the size of the profession more than quadrupled in the past 50 years, but other professions and businesses have also begun to perform services traditionally restricted to lawyers. For example, accounting firms have encroached on tax litigation, banks in the trusts and estates area, and financial planners in estate planning. In a series of cases, the United States Supreme Court has made it clear that lawyers cannot prevent the development of this competition from both within and without the legal profession