Corporate credit unions are united on a cooperative basis in the Central Credit Union (US Central Credit Union). The uniqueness of credit unions is that they put together the principles and benefits of financial cooperatives, consumer cooperatives and mutual aid funds, born once by trade unions. Specialization of credit unions to provide financial services to its shareholders requires a particularly strict regulation of membership and acceptable activities. The main advantage of credit unions consists in transparency, controllability, governance for shareholders. Since the early 80's started the process of consolidation of credit unions, leading to a decrease in their number with a simultaneous increase in the total number of members. National Credit Union Insurance Fund was created by Congress in 1970 to insure deposits of credit union members in the amount of 100 thousand dollars. Worldwide credit union movement is represented by regional confederations and national organizations within the World Council of Credit Unions.