On Monday morning, I popped into my nearest supermarket to buy some fruit, picking up an apple to chop up for breakfast.

But when I got to the counter, there was a problem.

The cashier tapped away on his screen before shaking his head and saying, ‘I can’t sell you that.’

‘Why not?’ I asked.

‘The computer says that I can only sell you apples in packets of six.’

I pointed out that the apple was one of a couple sitting in a fruit bay. 

‘They must have fallen out of a packet,’ the cashier said, taking the apple and moving it out of range. ‘There’s nothing I can do, I’m afraid.’

And so, with the gentlest of handbrake turns, to the Post Office Scandal and the shocking miscarriage of justice that saw almost 1,000 sub-postmasters prosecuted for theft and fraud. 

Following the ITV drama Mr Bates vs the Post Office, previously disinterested politicians have been falling over themselves to say how appalled they are by the whole situation. 

Not so appalled, of course, to take any responsibility for the situation. 

The Lib Dem leader, Ed Davey, who was the minister responsible for the Post Office between 2010 and 2012, refused ten times to say sorry in a TV interview. 

His then boss, David Cameron, went for the opposite tack, suggesting that ‘anyone who’s been involved in government in any way over the last twenty years has got to be extremely sorry’ – an apology so wide as to be completely meaningless. 

At the heart of the issue was a wonky Fujitsu computer system, Horizon. Horizon told the Post Office its sub-postmasters were stealing. 

The Post Office believed the computer programme over the sub-postmasters and took them to court. Computer Weekly first printed articles about the faulty system in 2009, but the prosecutions kept coming. 

Quite who worked out what was happening and when is the subject of a public inquiry and the private consciences of the individuals involved.

An underlying factor behind all this, perhaps, is the human propensity to cleave to authority. 

The famous Milgram Experiment of the 1960s, in which participants issued electric shocks when asked to, shows how many of us do what we’re told, rather than question whether that order is right or not.

Today, that authority figure is technology: if the programme says something is the case, whether it is post office fraud or apples not for sale, then it must be the case. 

Computers, however, are as fallible as those who programme them: Chat GPT, for example, will cheerfully make up facts and claim they’re true. 

Without proper oversight, the potential for AI to deliver future Post Office Scandals – and then some – is mailed on.