Did the IRS leak confidential information to other groups?

Congressional Republicans were all over this question Thursday and are certain to press for more details at Friday’s hearing.

They want to know whether the agency officials passed conservative groups’ confidential information to outside groups. And if so, how often.

Senate Republicans on Thursday asked the IRS inspector general to probe the agency’s release of private information from nine conservative groups whose application for a tax exemption was still under review.

The National Organization for Marriage this week also accused the IRS of leaking donor information — including GOP presidential hopeful Mitt Romney’s status as a contributor — to opponents at the Human Rights Campaign.