The whistle-blowing Web site WikiLeaks has not been convicted of a crime. The Justice Department has not even pressed charges over its disclosure of confidential State Department communications. Nonetheless, the financial industry is trying to shut it down.

Visa, MasterCard and PayPal announced in the past few weeks that they would not process any transaction intended for WikiLeaks. Earlier this month, Bank of America decided to join the group, arguing that WikiLeaks may be doing things that are “inconsistent with our internal policies for processing payments.”

The Federal Reserve, the banking regulator, allows this. Like other companies, banks can choose whom they do business with. Refusing to open an account for some undesirable entity is seen as reasonable risk management. The government even requires banks to keep an eye out for some shady businesses  like drug dealing and money laundering  and refuse to do business with those who engage in them.

But 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.