Wagner's charged as a conspirator. Photo by Paul Sakuma/AP

The U.S. Attorney's Office for the Northern District of California filed felony charges last week against Bryan Wagner, a Littleton, Colo., investigator who worked for Hewlett-Packard as the company tried to stop leaks to the media from members of its board. Those charges hint that others may be on the way.

Authorities charged Wagner with one count each of conspiracy and aggravated identity theft. The charges state that Wagner--and known and unknown co-conspirators--obtained and exchanged Social Security numbers, dates of birth, addresses, and other personal information of the people targeted in HP's probe in order to try to gain access to their personal phone records. Federal prosecutors are continuing to investigate; HP is cooperating with investigators and declined to comment on the charges against Wagner.

Late last year, California Attorney General Bill Lockyer indicted Wagner, other investigators, former HP counsel Kevin Hunsaker, and former HP chairwoman Patricia Dunn in the state's investigation of the conspiracy. They've all pleaded not guilty.