The Department of Justice prepares to bring charges against the credit ratings agency Standard & Poors for their part in the financial crisis of 2008. - 

The U.S.  Department of Justice -- along with the attorneys general in many states -- are reportedly set to file civil charges against the credit rating agency Standard & Poor's. The suit, which could be filed as early as this week, would allege that S&P fraudulently rated mortgage bonds in the lead up to the financial crisis.

S&P responded to news of the civil suit with a statement:

A DOJ lawsuit would be entirely without factual or legal merit. It would disregard the central facts that S&P reviewed the same subprime mortgage data as the rest of the market -- including U.S. Government officials who in 2007 publicly stated that problems in the subprime market appeared to be contained -- and that every CDO that DOJ has cited to us also independently received the same rating from another rating agency.

Since the financial crisis, critics have said the U.S. government failed to prosecute or punish Wall Street for many of the actions that led up to the crisis. Government prosecutors have argued that misdeeds in this arena are hard to prove.

"The behavior that brought the fiscal crisis was risky and stupid but perhaps not illegal," said Wall Street Journal reporter Evan Perez, who is covering the story. And S&P may be the first named in a suit, but they won't be the last. Perez says this is probably just beginning of a wider effort.

But how successful will it be? Ratings agencies in the past have cited the First Amendment -- that they have the right to say whatever they like about bonds. But that might not apply in the case of fraud -- which might be what the Justice Department will argue.

Follow Kai Ryssdal at @kairyssdal