Where BBC journalists go looking to make the news, by unearthing new facts or obtaining an admission from a politician or businessman, the same rules apply. Sending undercover cameramen into BNP meetings hoping to hear bad things being discussed? Sure. Sending them into mosques with the same brief? Er ... we'll leave that to Channel Four, thanks very much.
A favourite sport of Today presenters is to try and create the lunchtime news headlines by getting some interviewee to either "drop a clanger" or "reveal their real agenda", depending on your viewpoint. Even a Victoria Derbyshire can do it if the interviewee is ill-briefed and ill-prepared enough.
But sometimes the quest for what's perceived to be the killer admission can ruin the interview - for some reason I always think of Evan Davies interviewing anyone at all on drugs policy, where he seems incapable of keeping his personal enthusiasms in check.
And sometimes the quest for a not-very-important admission can blind the interviewer to the most remarkable statements being made by the interviewee - which go straight past the journalist's head because they're nothing to do with the little verbal traps he's setting.
That failure to actually listen to the interviewee constitutes IMHO diabolical journalism. John Humphrys (for it is he) should listen to his Patrick Mercer interview from yesterday morning, then tear up his NUJ card and announce his retirement.
The subject of the interview was a leaked letter written by Defence Secretary Liam Fox to the Prime Minister, expressing concern that the Government planned to make a legal commitment to increasing its overseas aid spending at a time when armed forces budgets are being cut heavily. The subtext of the interview, as Humphrys revealed, was Conservative division.
In the studio were Patrick Mercer, a former army officer and former Conservative security spokesman, broadly sympathetic to the Fox concerns, and Lib Dem MP Malcolm Bruce, very much against them. You'd imagine Mercer is reasonably close to current military thinking, and current M.O.D. thinking.
It was near the end of the interview, emboldening is mine :
"At a time when the armed forces are being cut and cut hard, when they're at war in Afghanistan, Pakistan and indeed in Libya, with other conflicts on the horizon ... you can see why the defence secretary is concerned"
Humphrys, completely missing the above and intent on his 'Tory division' narrative (I paraphrase) :
"But .. Liam Fox wrote to the Prime Minister and addressed him as 'Dear David Cameron' .. now we know he would like to be Tory leader - isn't there an ulterior motive?"
"at a time when money is stretched ... at a time when we are at war on at least two fronts, and probably a third front to come, no doubt Liam Fox is fighting his corner as any other Secretary of State would do".
Now it may be that Mercer's statement that we are at war in Pakistan is a slip of the tongue, and he's thinking of the Americans, who do seem to have made one or two trips across the Durand Line recently. But what are these "other conflicts on the horizon"? What is this "third front to come", assuming Front 1 to be Afghanistan and Front 2 Libya? Have I been asleep lately - should I know all about this war to come?
Syria ? Seems unlikely. Iran ? Ditto. Are the Argentinians planning another crack at the Falklands (and if they were, how could we possibly form a front down there once Mount Pleasant was lost, having no carrier capability?).
I would really love to have known what Mr Mercer was talking about - and I imagine BBC listeners might have been interested, too. Pity the BBC couldn't find a journalist to ask him!
(cross-posted at Biased-BBC)