A raft of high-profile celebrity test cases could lead to stronger penalties for media

It is a mark of the media frenzy over privacy injunctions that the topic has continued to hog the headlines even while a related issue of arguably far more significance has played out: the dramatic escalation of the phone-hacking scandal. True, the issue has dogged News International for years but it was only last month that the company issued an apology and moved to compensate victims – a measure that came a week after two senior News of the World (NoW) journalists were arrested on suspicion of unlawfully intercepting voicemail messages.

The latest developments last week (13 May) saw actress Sienna Miller (pictured) accept an offer from NoW after the paper admitted liability for her phone-hacking action. Her claim had involved misuse of private information, breach of confidence and harassment, and the settlement sees NoW admit liability and agree to disclose to Miller's legal team the extent of all wrongdoing. Mr Justice Vos is expected to issue his full judgment this week.

Legal fees for the case – Miller was represented by Matrix Chambers' increasingly ubiquitous Hugh Tomlinson QC alongside 5RB's David Sherborne and Atkins Thomson's Mark Thomson – are likely to have come in at twice the £100,000 accepted settlement offer. Anthony Hudson QC from Doughty Street Chambers, 11 South Square's Michael Silverleaf QC and Farrer & Co media partner Julian Pike represented NoW.

Even with this settlement, costs on the fast-evolving Hackgate saga look certain to be very substantial. Miller was one of four test cases that Vos identified after being assigned to manage claims relating to phone hacking. And the potential level of claims against NoW parent News International looks enormous. Ninety-one cases of alleged phone hacking have been identified according to the latest estimates from the police, but lawyers representing claimants argue the real number of victims could be in the thousands.

Other lawyers involved in related actions include Schillings partner John Kelly for football pundit Andy Gray and comedian Steve Coogan and Mishcon de Reya partner Charlotte Harris, who is representing a number of potential claimants including football agent Sky Andrew, Leslie Ash and her husband Lee Chapman. Harris herself looks in danger of edging out Tomlinson as the public face of privacy law after featuring heavily in the media last week before acquitting herself well in a punchy debate on injuctions on Newsnight alongside the actor Hugh Grant.

The key question for many media lawyers is whether Hackgate will finally lead to the imposition of exemplary damages for privacy claims. Indeed, Miller's settlement is a good deal higher than the level of awards that have previously been made in privacy cases. Max Mosley received one of the highest awards in his legal battle with NoW when he was given £60,000, while Naomi Campbell famously won a test case on privacy against Mirror Group Newspapers, but only received £3,500.

Yet the expectation among media lawyers has for years been that the courts will eventually move to bring in stronger penalties for breaches of privacy and, if any case looks likely to get us there, this is it. The prospect of a group of angry, well-heeled claimants moving in the wake of well-established test cases will be worrying for NoW. In addition, there will be much attention focused on whether anyone will attempt to bring claims before the US courts, potentially increasing costs hugely. While News International is hoping to settle all claims for around £20m, some lawyers are putting the potential higher – much, much higher. Given such an outlook, it is little wonder that some of the print media have been so quick to put the emphasis back on the supposed introduction of 'back-door privacy laws'.