Is There a Government Blacklist Delaying Citizenship for Muslims?

Thirteen Muslims in Missouri are suing the federal government after claiming there’s a “blacklist” delaying citizenship for Muslim applicants.  The application review program adopted by U.S. Citizenship & Immigration, CAARP, is a so-called “secret” program that “allows them to basically presume that people are terrorists.”
The USCIS counters that the agency doesn’t comment on pending litigation, and each application is reviewed on a “case by case” basis.