650,000 consumers left big banks to join credit unions in the past month, ahead of Bank Transfer Day, according to Credit Union National Association (CUNA).

Bank Transfer Day happened Nov. 4, 2011. It was the brainchild of a fed up consumer, Kristen Christian, who set up a Facebook page to encourage people to send big banks like Chase, Citigroup, and Bank of America a message by transferring their accounts to credit unions or smaller banks that presumably would provide more personalized service and not have excessive fees. Even though Bank of America backed down from its plans to charge most of its individual account holders a $5 a month fee for the privilege of accessing their own money via a debit card, and other banks followed suit, consumers are still mistrustful. Will big banks continue to seek ways to recoup their lost profits from the new consumer protection laws that among many changes lowered the swipe fees banks could charge merchants for every debit card transaction.

If one person can set up a Facebook page and get more than 80,000 people to pledge to close their bank accounts with big banks, where does it end? After all, governments have fallen in the Middle East during the Arab Spring, thanks in part to the power of social media to unit people in protest. Now Occupy Wall Street has captures the imagination of Americans fed up with income inequality, and the sense that the levers of power around the world are controlled entirely by the financial elite. When voting doesn’t seem to change anything, more people are captivated by the idea that change can happen when people unite in collective actions such as public demonstrations, boycotts of certain products, or selective transactions.

Can just 80,000 people moving their money into credit unions make a difference? According to Forbes magazine: “If the 80,000 signed up for Bank Transfer Day indeed move their money, they stand to save a combined $4.8 million a year as credit union members save on banking fees, states Bill Cheney, CEO of CUNA. If over 400,000 consumers made the switch, they’d stand to save about $29.8 million just by joining a credit union. When you look at what consumers could gain and not just what banks would lose, it becomes a positive movement with long-standing legs.”

Think about the environmental movement and the countless concessions big businesses have made to “go green.” Grocery stores now all offer reusable grocery bags as an option at check out, for example. Trucking companies are switching to bio-diesel fuels.

People are outraged at other fees such as overdraft fees and transfer fees. And small business owners are frustrated that banks have tightened up their lending policies to the point that it is very difficult for them to get loan to expand their business. While banks have not signalled any concern about individuals closing their accounts, since each account does not represent a large deposit, they have discussed concerns about business closing business accounts. If enough small businesses closed their accounts, it would likely result in banks pivoting to create new programs to try and lure them back, or keep them from leaving in the first place. In the end, the power of the purse is the best lever individuals have, because when they band together in collective action such as Bank Transfer Day, it gets the attention of the media, and in turn, attention of big business, politicians, and big finance.