The Petraeus scandal is receiving intense media scrutiny obviously due to its salacious aspects, leaving one, as always, to fantasize about what a stellar press corps we would have if they devoted a tiny fraction of this energy to dissecting non-sex political scandals (this unintentionally amusing New York Times headline from this morning - "Concern Grows Over Top Military Officers' Ethics" - illustrates that point: with all the crimes committed by the US military over the last decade and long before, it's only adultery that causes "concern" over their "ethics"). Nonetheless, several of the emerging revelations are genuinely valuable, particularly those involving the conduct of the FBI and the reach of the US surveillance state.
As is now widely reported, the FBI investigation began when Jill Kelley - a Tampa socialite friendly with Petraeus (and apparently very friendly with Gen. John Allen, the four-star U.S. commander of the war in Afghanistan) - received a half-dozen or so anonymous emails that she found vaguely threatening. She then informed a friend of hers who was an FBI agent, and a major FBI investigation was then launched that set out to determine the identity of the anonymous emailer.
That is the first disturbing fact: it appears that the FBI not only devoted substantial resources, but also engaged in highly invasive surveillance, for no reason other than to do a personal favor for a friend of one of its agents, to find out who was very mildly harassing her by email. The emails Kelley received were, as the Daily Beast reports, quite banal and clearly not an event that warranted an FBI investigation: