As with any private business or industry in a capitalist system such as ours, the main goal and purpose is to turn a profit, to make money. So part of the need and justification for consumer protections and regulation of such large and important industries as banking and telecommunications stems from the fact that, without such rules, there is a tendency to exploit and/or abuse consumers.
Often times, even the majority of times, profit and consumer safety are at odds with one another, and there is great temptation in banking to add fees to any variety of services or situations, as we recently saw with Bank of America seeking to charge for debit card use, or in the very high credit card interest rates and overdraft fees. Without some measure of protection against such practices, abuse is very likely to take place. The same is true of telecommunications, with variable cell phone call rates, hidden fees and taxes, surcharges, and long term contracts, it is also an industry that needs oversight and regulation from time to time.