When Big Banks nickel and dime you with fees on just about everything from checking accounts to ATMs to debit cards, they turn those nickels and dimes into billions of profits.

On Saturday, consumers struck back with “Bank Transfer Day,” when they switched from behemoth banks like Bank of America (BofA), Chase and Citi to non-profit credit unions. But Saturday was just one day in what has been a steady stream of movement over the past month away from corporate banks.

It’s too early to tell how many made the switch on Saturday, but since Sept. 29, when BofA announced it would charge consumers a monthly fee for debit card purchases—that it dropped a few days ago, following public outrage—more than 650,000 people opened new accounts with credit unions, according to the Credit Union National Association. The group says its members attributed most of the upsurge to consumers fed up with bank fees and to the publicity Bank Transfer Day received.

Bank Transfer Day was the idea of 27-year-old Los Angeles art gallery owner Kristen Christian who, a month ago, started a Facebook page (now with nearly 60,000 likes) to promote the protest against Big Bank greed. She wrote:

Together we can ensure that these banking institutions will always remember the 5th of November. If we shift our funds from the for-profit banking institutions in favor of not-for-profit credit unions before this date, we will send a clear message that conscious consumers won’t support companies with unethical business practices.

The Bank Transfer Day event page drew nearly 86,000 people who said they would “attend.” Reports from around the country showed credit unions saw a big bump in traffic Saturday. Check out this press release from the Texas Credit Union League.

Texas Credit unions had a steady stream of new accounts open on Saturday as “Bank Transfer Day” drew attention online and on the streets across the state. While statistics for Bank Transfer Day are not yet available, credit unions reported a surge in traffic. Statewide, credit unions reported 47,000 Texans had joined, and $326 million was moved by Nov. 2—four times the usual growth rate.

Here’s a question: If banks so love what they portray as small convenience fees on everyday transactions, why are they so riled up about the tiny fees a Robin Hood tax would put on financial transactions and speculation?  That’s a rant for another day.