One of the first concepts you learn at journalism college is the principle of open justice – that it is important in a functioning, fair society for justice to be seen to be done.

That’s why courts are open to the public and why the press is encouraged to report on them.

It’s important so the public can have faith in the justice system whose rules we are all expected to respect, and so that where the system fails to earn that respect – say, when prosecutions are low, or wrongful – we know about it.

It’s also important to reassure the public that criminals are being caught and taken to task, both to deter would-be lawbreakers and to remind us we can walk the streets (relatively) safely.

Given recent incidents involving knife crime in West Hampstead, you might think it particularly important we report on the case of the 16-year-old boy who has denied GBH after a stabbing in Billy Fury Way earlier this month. Is he innocent? If not, what happened? Can we stop it happening again?

So let’s say we decide to go to court. The case will be catalogued using the name of the defendant, meaning we need that name to find out which court to turn up to and when, and then which of the scores of cases being heard each day is the relevant one.

Yet the police wouldn’t give us the boy’s name – even though they’ve charged him – because it’s Met policy not to name defendants under 18, even on a not-for-publication basis. Harry argued the toss, then I waded in, and they still wouldn’t budge. (We managed to get the name from a different source, but that’s hardly the point.)

There is such a thing as anonymity for juveniles, which can be ordered by a judge. But the point of that is to stop a defendant or witness being named as we report on cases, not to kick us out of court altogether. What the Met is doing is obstructing open justice for the sake of its own internal processes. There are already rules about what we can and can’t cover in a trial – we don’t need the police to add obstacles for which they have no legal grounds.