It took the arrest of five journalists from The Sun to put Lord Justice Leveson's examination of our newspapers into context. At the end of last week, it would have been possible to believe that the most significant aspect of the inquiry into press standards was the dispute between Hugh Grant and the editor of the Daily Mail over a woman with a posh voice.

But these latest arrests remind us the real action is taking place not in the Royal Courts of Justice, but at Scotland Yard, where the Met is desperately trying to play catch-up for its earlier lack of probity. There's little doubt the inquiry has served a valuable purpose in shining a light on dubious journalistic practices and in giving a voice to those who have suffered outrageous injustice and I'm sure in time it will come to be regarded as some sort of catharsis.

But, over the 40 days of the inquiry, the impression has been given that the entire newspaper industry is on trial.

This is both insidious and dangerous. We are at this point because of allegations of widespread criminality at one particular newspaper group and these arrests serve only to underline that.

Nevertheless, we have now reached the end of the beginning of the inquiry, so it does seem an appropriate juncture to comment on what Lord Justice Leveson called "the direction of travel" of the investigation. First, I wonder if any trade or profession in Britain would survive with its reputation intact from such a forensic examination of its culture, practice and ethics? And I'm not just talking here about bankers or MPs, who everyone would like to see put on oath and then in the stocks.

But what about builders, accountants, doctors or even, heaven forbid, lawyers? If every day, live on a screen near you, there was a well-known silk in the dock being interrogated about how they go about their business, I'm pretty sure that a shocking picture of our legal system would soon be sketched out and the public would begin to lose confidence in a key instrument of democracy.

Thus it is with newspapers. As Lord Justice Leveson said at the outset: "I fully consider... freedom of the press to be fundamental to our democracy, fundamental to our way of life." Yet, that's not what it looks like. For instance, Heather Mills or Alastair Campbell – people who have shamelessly sought to use the press to further their own ends – are able to present themselves as hapless victims, while newspaper editors come across as defensive, even shifty.

It may be a welcome turning of the tables, but does that really serve the interests of the public or even the wider purpose of the inquiry? And while there are many in Britain who might enjoy the sight of the editor of the Daily Mail, a powerful man and the ruler of his own dominion, appearing as if he was nicked for burglary, it doesn't get us anywhere. The real charges will be laid at a later date and it's as well to remember that.

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