An atheist group named Freedom From Religion Foundation, and Citizens for Responsibility and Ethics in Washington filed a lawsuit against HUD. According to Newsmax, "Carson was named as a defendant in the lawsuit in his capacity as HUD secretary." White House officials including sometimes President Donald Trump meets every week at the White House for a Bible study.
The atheist groups filed an FOIA request to see if government funds are being used for the Bible study and to find out if people are being pushed or pressured to attend the meetings. They are upset that they have to pay for the request and in turn decided to sue the government because of it.