Witch-hunts have long held a special place in the administration of justice.
From the Inquisition through to Uncle Joe Stalin to Senator Joseph McCarthy and onwards to the Taliban, the methods may change but the aim is fundamentally the same: to impose a single will by authoritarian means.
Senator Joe's infamous question was: "Are you now or have you ever been a member of the Communist Party of the United States?" Those who tried to invoke the constituional First Amendment's guarantee of freedom of speech were overruled and jailed.
So if you have ever worked in the media, think long and hard before answering the 2012 UK adaptation of the question that now reads, courtesy of a fellow-journalist whose name has slipped my mind: "Are you now or have you ever been a journalist?"
A No opens the door to rigorous investigation. So does a Yes, which will also be taken as admission of guilt to some real or imagined crime or misdemeanour. Don't even consider Maybe.
A Yes is aggravated significantly if it places you somewhere in the printed press. If your part of the printed press was or, worse still, is considered tabloid, then you should be putting your affairs in order prior to a spell in jail.
It does not matter a jot whether everything you have ever done in the pursuance of your trade has been free of any trace of wrongdoing. If it is good enough for the libel laws of the land, it is good enough for you: guilty until proved innocent, bearing in mind the prospects of getting a fair-minded jury in the present climate of hysteria and hypocrisy are on the low side. Journalist + print + tabloid is, put simply, a recipe for evil.
And don't think for a second that denial of any link to tabloid journalism - which these days could, of course, include The Times, Indie and Graun whatever fancy names they give their shapes - is a passport to acquittal. They're out to get you.
Even if you are not, and never have been, a journalist, it should be borne in mind that it is also a risky business having had the least contact with members of the press.
The Telegraph reported last month that a City of London police superintendent had been arrested on suspicion of passing unauthorised information to a journalist. There was no question of a corrupt payment, or indeed any payment at all, but there was the suspicion of "misconduct in a public office".
Now it may be that the officer in question is suspected of giving some reporter a piece of gossip that seriously jeopardised an investigation or put national or City of London security at risk. Or "misconduct in a public office" may turn out to be a chilling phrase to cover the act of giving an honest answer to an entirely reasonable question. If the former, I will cheerfully acknowledge there may be a case to answer; at this stage, we do not know.
But am I alone in being worried that we are now well on our way to living in a society where all information given by public officials and services will take the form of press releases and that anyone who fleshes out, clarifies or even corrects the details provided will be liable to arrest? And woe betide any journalist who does his or her job and attempts to find out more.
I am reminded of three blasts from the past.
* when the Devon schoolgirl Genette Tate vanished without trace in the 1980s, the media - representing national broadsheets, tabloids, local papers, news agencies, television and radio - descended on her home village of Aylesbeare.
The inquiry was led by an experienced and well-respected detective with the wonderful name of Proven Sharpe. What went on between him and his colleagues and the more diligent of the reporters present was of undoubted public service but would have got everyone arrested in these grim times for news gathering.
There would be regular contact, encouraged by an enlightened chief constable, John Alderson, who had stipulated that every officer in his force from constable upwards was permitted to talk to journalists subject to the proper limits of their knowledge - and, heaven forbid, meals and drink would sometimes be shared. The hacks picked up the bills because they could. Ideas for keeping the search for poor Genette prominent in the public eye were exchanged and, in some cases, acted upon. It didn't lead to her discovery but was worth a try. Relations were amiable but, so far as I could tell, correct but what was discussed necessarily went beyond bland press release content (good as the Devon and Cornwall police press office of the day happened to be).
* policy on contact with the press varied even then. Anecdote; man asks a Metropolitan police sergeant the way to the local nick. "Aren't you a journalist?" the officer replies. "You should know better than to ask me that. You must address your question to the Scotland Yard press bureau."
* in his admirable autobiography,Life Between the Lines (Umbria Press) - of which much more later - the distinguished former Daily Telegraph education correspondent John Izbicki, who later played an important role in higher education policy, makes a candid admission. Covering a Dartmoor prison escape as a young reporter, he joined a Times colleague, Roger Mount, in listening to police broadcasts on a shortwave radio.
"The police did start smelling a rat when Roger and I kept turning up at places indicated on their radio - sometimes even well before they managed to get there themselves. But they never made a fuss about this and didn't even bother to broach the subject. We never got in their way and, if anything, proved helpful - especially in providing the odd crate of beer in the evenings."
I saw John recently at the launch of his book in a Fleet Street pub. Despite his advancing years, he looked in great shape. Just as well since he can now expect at least two separate knocks on the door and needs to keep his wits about him.
Not for the first time, I acknowledge that hacking phones and e-mail accounts, and systematically paying coppers for information, strike me as alien to the life I have led as a journalist. In serious cases, subject to a public interest defence that does not even exist, some degree of punishment is justifiable. The press has brought a lot of its present problems crashing down on its own head. But I also repeat that there are few trades and professions - whether or not they have their own disciplinary arms - that would stand up to Leveson-style scrutiny much better than the press has.
Only the middle one of my "blasts from the past" was made up (by a friend), but it gives you an idea of a future in which the flow of information will be strictly controlled in ways that would have brought smiles to the faces of Orwell's characters in 1984.
Bill Taylor, commenting here on an earlier piece, got it in one when he cited a quotation from the French-Algerian winner of a Nobel prize for literature Albert Camus: "A free press can, of course, be good or bad but most certainly without freedom the press will never be anything but bad." The photo I borrowed from Flickr, thanks to Creative Commons, had a caption saying "the printed newspaper isn't as common as it used to be".
That could almost be engraved on the tombstone of the industry. Leveson may be listening. Scotland Yard is unlikely to be.