Another nail in the coffin... 
According to a recent unclassified report to Congress, the FBI expects its informants to provide secrets about possible terrorists and foreign spies, although some may also be expected to aid with criminal investigations, in the tradition of law enforcement confidential informants. The FBI did not respond to requests for comment on this story.
The aggressive push for more secret informants appears to be part of a new effort to grow its intelligence and counterterrorism efforts. Other recent proposals include expanding its collection and analysis of data on U.S. persons, retaining years' worth of Americans' phone records and even increasing so-called "black bag" secret entry operations.