This David Petraeus sex scandal has, as is usually the case, launched thousands of columns claiming to understand intimate details about the mental states of everyone involved, striking moral tones about who can be blamed and what it means for the moral fabric of family life in America, the military, what have you. But the really interesting and important aspect of this story is the degree to which the FBI completely abuses the public trust, apparently for no more a reason than a favor to a friend.

Consider the origins of this case. Paula Broadwell, Petraeus’ mistress and biographer, sent some vaguely angry emails to Jill Kelley, who is described as an “unpaid social liaison at MacDill Air Force Base, Florida.” Broadwell allegedly saw Kelley groping Petraeus under a table, and sent Kelley emails – she hacked into Petraeus’ off-books email account to get the address – that really didn’t say anything threatening.

But Kelley had a hold card – a friend at the FBI. Specifically, a friend at the FBI who wanted to get into her pants.

Ms. Kelley, a volunteer with wounded veterans and military families, brought her complaint to a rank-and-file agent she knew from a previous encounter with the F.B.I. office, the official also said. That agent, who had previously pursued a friendship with Ms. Kelley and had earlier sent her shirtless photographs of himself, was “just a conduit” for the complaint, he said. He had no training in cybercrime, was not part of the cyber squad handling the case and was never assigned to the investigation.

But the agent, who was not identified, continued to “nose around” about the case, and eventually his superiors “told him to stay the hell away from it, and he was not invited to briefings,” the official said [...]

Later, the agent became convinced — incorrectly, the official said — that the case had stalled. Because of his “worldview,” as the official put it, he suspected a politically motivated cover-up to protect President Obama. The agent alerted Eric Cantor, the House majority leader, who called the F.B.I. director, Robert S. Mueller III, on Oct. 31 to tell him of the agent’s concerns.

OK, so the FBI has someone on their payroll who likes to sext. But he also likes to cajole his colleagues into investigating a case of unwanted cyberstalking emails, without actual threats attached to them. And from this, they basically commandeer the private communications of multiple people. Today we learn about inappropriate communications between Kelley and John Allen, the NATO commander for Afghanistan, who replaced Petraeus there (it’s on the order of hundreds of emails, not 20-30,000 as first reported). What does this have to do with the Kelley-Broadwell-Petraeus case? Who at the FBI leaked the Allen investigation, which appears to be about at most flirtatious emails only and probably not even a crime?

Because this cybercrime investigation eventually involved high-ranking national security figures, and fundamentally became a security scandal, with Petreaus allowing Broadwell access to secret information, that perhaps justifies the FBI’s interest in the case. But this is all after the fact. At the outset, the FBI had a tip from someone about six harassing emails. Why did they start in on this to begin with? And how much power have we handed over to a domestic agency, which can apparently sequester and geo-locate any email account on the planet? And this was all done without informing members of Congress, unless you count Agent Shirtless thinking that slow-walking in the case represented an Obama plot, leading him to spill his guts to Eric Cantor.

So this is not a scandal about sex, to me. It’s about the power of the surveillance state.