ADRIENE HILL: You may know Capital One from their off-beat and often-aired “What’s in your wallet?” ads. You know, with the vikings and barbarians. But Capital One is more than a credit card company. Over the last few years, it’s snatched up three retail banks. Now, it wants to conquer online. But some consumer groups say not so fast — they worry the bank’s grown too big, too fast.

From Washington, Marketplace’s David Gura reports.

DAVID GURA: Capital One’s offered to buy ING Direct for about $9 billion in cash and stock. For that kind of money, what would it get?

Henry Coffey is an analyst with Sterne Agee.

HENRY COFFEY: A bunch of deposits, a bunch of investments, a bunch of cash, plus this very robust platform.

ING’s web-based bank. It’s a direct depository — a bank with no branches.

COFFEY: From a bank’s point of view, you get the ability to grow and scale an operation without having to invest in a lot of bricks and mortar.

Capital One announced the deal in June, and since then, many consumer groups have spoken out against it. John Taylor heads the National Community Reinvestment Coalition.

JOHN TAYLOR: They’re actually creating, believe it or not, the fifth-largest depository institution in the United States.

He argues Capital One’s acquisitions haven’t benefited consumers, that the bank has lent less and less money to small businesses and offers fewer government-backed mortgages. And Taylor says the last thing the U.S. needs is another big bank, especially as regulators decide what institutions, if any, are too big to fail.

KAREN PETROU: Everybody’s waiting, but it hasn’t come out.

That’s Karen Petrou, with Federal Financial Analytics.

Last week, Congressman Barney Frank asked the Federal Reserve to take more time to decide if the acquisition passes muster. Capital One wouldn’t talk to us, but a bank spokesman said in a statement the deal wouldn’t “result in greater risk to the stability of the U.S. banking system.”

In Washington, I’m David Gura for Marketplace.