A source just dropped me a line:

About 20 fully-armed federal IRS agents swarmed into the Franke Building at 171 Church Street this morning.

We’re checking on it and will follow up later.

UPDATE: IRS confirmed the event. Other than that, they ain’t talkin’.

UPDATE 2: The U.S. Attorney’s Office in Columbia said that agents were still on scene this afternoon, but that the warrant that would provide more information regarding the search will not be available for several days.