The celebrated writer William Vollmann has revealed that the FBI once thought he might be the Unabomber, the anthrax mailer and a terrorist training with the Afghan mujahideen.

In the September issue of Harper’s magazine, Vollmann describes the alarming and ludicrous contents of his 785-page secret government file, 294 pages of which he obtained after suing the FBI and CIA under the Freedom of Information Act. (Update: You can see some pages of his file here.) Spiked with sarcasm directed at what he sees as the agencies’ arrogance, presumptuousness and ineptitude, his Harper’s essay, “Life As a Terrorist,” is inflamed with moral outrage at the systemic violation of his privacy. “I begin to see how government haters are made,” he writes.

A winner of the National Book Award and a finalist for the National Book Critics Circle Award, Vollmann is considered one of the most insightful writers in the world on the subject of violence and war. His acerbic exposé in Harper’s about the government’s decades-long investigation into his personal life follows a series of recent revelations about National Security Agency surveillance. A Washington Post report Wednesday said that a secret court opinion in 2011 found the NSA had “unlawfully gathered tens of thousands of e-mails and other electronic communications between Americans as part of a now-revised collection method.”

“Reading one’s FBI file is rarely pleasant,” Vollmann writes. He discovered that someone — Vollmann gives him the codename “Ratfink” — turned him in to the authorities as a possible Unabomber suspect because of the content of his fiction. His file claims that “anti-growth and anti-progress themes persist throughout each VOLLMANN work.” In this case, his accuser was referring to “Fathers and Crows,” a novel “set mostly in Canada in the seventeenth century.” Even more conclusive, the FBI observed ominously that “UNABOMBER, not unlike VOLLMANN has pride of authorship and insists his book be published without editing.”

What more evidence do we need!?

It’s hard to decide if we should be more concerned about what he describes as the agency’s nefariousness or its stupidity. Vollmann notes that the FBI couldn’t determine his Social Security number because it spelled his name wrong. His file incorrectly claims that he owns a flamethrower. (“I would love to own a flamethrower,” he writes.) It erroneously records him traveling to Beirut. In 1995, he was labeled “ARMED AND DANGEROUS.”

He makes hand-made art books.

Perhaps most alarming, he discovered in his heavily redacted file that he was considered a terrorist suspect even after the Unabomber had been apprehended in 1996. After the 9/11 attacks, he realizes, “I had graduated from being a Unabomber suspect to being an anthrax suspect.” Even today, his international mail often arrives opened. A private investigator explains to him: “Once you’re a suspect and you’re in the system, that ain’t goin’ away. . . . Anytime there’s a terrorist investigation, your name’s gonna come up.”

It’s a terrifying essay, only sporadically leavened by gallows humor. Vollmann admits that he’s hardly the worst victim of our overzealous government. But anyone who cares about the unraveling of our civil rights and the destruction of the American way of life should heed this chilling and deeply personal story. What he describes is a mostly invisible and completely impervious class of bureaucrats — he calls them “the Unamericans” — who systematically violate our privacy and disregard the presumption of innocence. The worst irony, of course, is they do this under the guise of protecting us.

UPDATE: Vollmann speaks with NPR about his FBI file.