I like to think that some of the things I write cause discomfort in those readers who deserve to feel it. Ideally, they should squirm, they should flinch, they might even experience fleeting gastro-intestinal symptoms. But I have always drawn the line at torture. It may be unpleasant to read some of my writings, especially if they have been assigned by a professor, but it should not result in uncontrollable screaming, genital mutilation or significant blood loss.

With such stringent journalistic ethics in place, I was shocked to read online a Mail on Sunday article headed "Food writer's online guide to building an H-bomb ... the 'evidence' that put this man in Guantánamo." The "food writer" was identified as me, and the story began: "A British 'resident' held at Guantánamo Bay was identified as a terrorist after confessing he had visited a 'joke' website on how to build a nuclear weapon, it was revealed last night. Binyam Mohamed, a former UK asylum seeker - who has in recent weeks become the subject of an ongoing political and judicial controversy in Britain - admitted to having read the 'instructions' after allegedly being beaten, hung up by his wrists for a week and having a gun held to his head in a Pakistani jail."

While I am not, and have never been, a "food writer", other details about the "joke" rang true, such as the names of my co-authors, Peter Biskind and physicist Michio Kaku. Rewind to 1979, when Peter and I were working for a now-defunct leftwing magazine named Seven Days. The government had just suppressed the publication of another magazine, the Progressive, for attempting to print an article called "The H-Bomb Secret". I don't remember that article and the current editor of the Progressive recalls only that it contained a lot of physics and was "Greek to me". Both in solidarity with The Progressive and in defence of free speech, we at Seven Days decided to do a satirical article entitled "How to Make Your Own H-Bomb," offering step-by-step instructions for assembling a bomb using equipment available in one's own home.

The satire was not subtle. After discussing the toxicity of plutonium, we advised that to avoid ingesting it orally, "Never make an A-bomb on an empty stomach", and explained that the challenge of enriching uranium hexafluoride, which included the instruction: "Attach a six-foot rope to a bucket handle. Now swing the rope (and bucket) around your head as fast as possible. Keep this up for about 45 minutes. Slow down gradually, and very gently put the bucket on the floor. The U-235, which is lighter, will have risen to the top, where it can be skimmed off like cream."

Our H-bomb cover story created a bit of a stir at the time, then vanished into the attics and garages of former Seven Days staffers, only to resurface, at least in part, on the internet in the early 2000s. Today, you can find it quoted on the blog spot of a University of Dayton undergraduate, along with the flattering comment: "This forum post is priceless. It is one of the best pieces of scientific satire I have ever seen. I can only hope and pray that terrorist groups attempt to construct an atomic bomb using these instructions - if they survive the attempt, they'll have at least wasted months of effort."

Enter Binyam Mohamed, an Ethiopian refugee and legal resident of Britain who had found work as a janitor after drug problems derailed his college career. According to his lawyer, Clive Stafford Smith, Mohamed travelled to Afghanistan in 2001, attracted by the Taliban's drug-free way of life. War soon drove him out of Afghanistan and to Karachi, from where he sought to return to Britain. But, as a refugee, he lacked a proper passport and was using a friend's, which led to his apprehension at the airport. Stafford Smith says the Pakistanis turned him over to the FBI, who were obsessed at the time with the possibility of an al-Qaida nuclear attack. After repeated beatings and hanging by the wrists, Mohamed "confessed" to having read an online article on how to make an H-bomb, insisting to his interrogators that it was a "joke".

But post-9/11 America was an irony-free zone, and it's still illegal to banter about bombs in the presence of airport security staff. It's not clear how the news of Mohamed's H-bomb knowledge was conveyed to Washington - many documents remain classified or have not been released - but Stafford Smith speculates that the part about the H-bomb got through, although not the part about the joke. The result, anyhow, was that Mohamed was thrust into a world of unending pain - tortured at the US prison in Baghram, rendered to Morocco for 18 months of further torture, including repeated cutting of his penis with a scalpel, and finally landing in Guantánamo for almost five years of more mundane abuse.

As if that were not enough for a satirist to have on her conscience, the US seems to have attributed Mohamed's presumed nuclear ambitions to a second man, an American citizen named Jose Padilla, aka the "dirty bomber". The apparent evidence? Padilla had been scheduled to fly on the same flight out of Karachi that Mohamed had a ticket for, so obviously they must have been confederates. Commenting on Padilla's apprehension in 2002, the Chicago Sun-Times editorialised: "We castigate ourselves for failing to grasp the reality of what [the alleged terrorists] are trying to do, but perhaps that is a good thing. We should have difficulty staring evil in the face."

I am not histrionic enough to imagine myself in any way responsible for the torments suffered by Mohamed and Padilla - at least no more responsible than any other American who failed to rise up in revolutionary anger against the Bush terror regime. No, I'm too busy seething over another irony: whenever I've complained about my country's torturings, renderings, detentions, etc, there's always been some smug bastard ready to respond that these measures are what guarantee smart-alecky writers like myself our freedom of speech. Well, we had a government so vicious and impenetrably stupid that it managed to take my freedom of speech and turn it into someone else's living hell.

• Barbara Ehrenreich is the author of This Land Is Their Land: Reports from a Divided Nation

Ehrenreichbooks@gmail.com