WASHINGTON – The way the FBI responded to Jill Kelley’s complaint about receiving harassing emails, which ultimately unraveled or scarred the careers of ex-CIA Director David Petraeus and Marine Gen. John Allen, is the exception, not the rule.

The FBI commonly declines to pursue cyberstalking cases without compelling evidence of serious or imminent harm to an individual, victims of online harassment, advocacy groups and computer crime experts told The Associated Press.

But in the sensational episode that uncovered the spy chief’s adulterous affair, the FBI’s cyberdivision devoted months of tedious investigative work to uncover who had sent insulting and anonymous messages about Kelley, the Florida socialite who was friendly with Petraeus and Allen – and friends with a veteran FBI counterterrorism agent in Tampa.