editorial in the New York Times suggests that it's not that simple:
...a bank’s ability to block payments to a legal entity raises a troubling prospect. A handful of big banks could potentially bar any organization they disliked from the payments system, essentially cutting them off from the world economy.
The Bank of America could be a case in point, with implications for free speech and a free press:
...The decisions to bar the organization came after its founder, Julian Assange, said that next year it will release data revealing corruption in the financial industry. In 2009, Mr. Assange said that WikiLeaks had the hard drive of a Bank of America executive.
What would happen if a clutch of big banks decided that a particularly irksome blogger or other organization was “too risky”? What if they decided — one by one — to shut down financial access to a newspaper that was about to reveal irksome truths about their operations? This decision should not be left solely up to business-as-usual among the banks.