WSJ:

Under the Community Reinvestment Act (itself a causal factor in the subprime mortgage debacle that has cost us all so dearly), there is a procedure for protesting, and significantly delaying, bank merger and branching applications if the parties involved have not "adequately" served the needs of the local community.

Particularly after the passage of interstate banking laws in the mid-80s, Acorn and other activist groups seized on this process as a way to extract money from banks. Acorn would protest applications, thereby significantly delaying regulatory action, unless the banks committed to fund targeted loan pools, "education" efforts conducted by Acorn, "consulting" contracts and grants to Acorn, etc. The banks had compelling business reasons to close the deals quickly. Bank regulators, especially the Fed, for political reasons shamelessly pressed the banks hard to settle with Acorn, et al., and the banks ponied up millions.

I did mergers and acquisitions for a regional bank and experienced Acorn's thuggish "negotiating" tactics and bad faith firsthand.