M&I Bank denies making contributions to Gov. Scott Walker with the old "corporations aren't permitted to make campaign contributions." (Which isn't exactly true anymore since Citizens United, but perhaps Wisconsin has its own restrictions. Whatever.) In any event, bank executives and employees are seen as strong backers of Walker, and now that's made them a target:

Madison -- Teachers, firefighters and police officers said they would begin a boycott of M&I Bank if the bank does not begin publicly opposing Gov. Scott Walker's efforts to curtail collective bargaining for public workers. Unions representing those groups said they would start other boycotts of businesses that backed Walker in his campaign. The letter to M&I President Tom Ellis said the boycott would begin March 17 if the bank hasn't opposed Walker's efforts by then. "In the event that you cannot support this effort to save collective bargaining, please be advised that the undersigned will publicly and formally boycott the goods and services provided by your company," the letter says. "However, if you join us, we will do everything in our power to publicly celebrate your partnership in the fight to preserve the right of public employees to be heard at the bargaining table."

So many protesters showed up, they had to close the bank:

M&I Bank's branch on the Capitol Square, at 1 W. Main St., closed Thursday after demonstrators, protesting campaign contributions by bank executives to Gov. Scott Walker, gathered outside the bank and several pulled their money out. Sara Schmitz, a spokeswoman for M&I in Milwaukee, said in an e-mail the bank shut its doors "under the advisement of the Madison Police Department and due to the significant number of protesters surrounding the Capitol." Madison police said hundreds of people had gathered at the front entrance to the bank. "(The) concern was if the crowd continued to grow, it would be difficult for us to guarantee access and safety for those trying to get in and out of the bank," police spokesman Joel DeSpain said. He said police did not tell M&I officials to close the bank. Members of several labor unions stopped at M&I twice between 9 and 9:30 a.m., said Joe Conway, Jr., president of Local 311 of the International Association of Fire Fighters. The protest was peaceful, he said. Several protesters went inside and closed their accounts, displaying checks that totaled $192,000 withdrawn, Conway said. Schmitz declined to comment about any withdrawals.

More at Daily Kos.