It is sometimes said that newspapers shouldn’t be regulated at all, that the law alone should be enough to set limits on the culture, ethics and practices of the press. If only the police had done their job properly, this argument runs, there would never have been any call for the Leveson Inquiry and the Royal Charter.Like so many of the self-serving or evasive arguments put forward by press bosses and columnists, this one does not stand up to any real scrutiny.Here are five reasons why relying on the law alone cannot work.1. The law does not deter repeat illegality. If the law alone was enough it would deter repeat offending, yet whole gangs of newspapers libelled Robert Murat, then repeat offended against Kate and Gerry McCann and then repeat offended a third time against Christopher Jefferies (and these are not the only cases). The papers monster their victims, are sued, apologise, pay up (relatively small sums) and just do it again. The papers concerned seemed to treat the penalties as if they were fees for exclusives, rather than fines for breaking the law.2. Breaches of the law are often difficult to detect. Many of the kinds of wrongs committed by the press, such as data theft and privacy intrusion, are never likely to be noticed by the victims or uncovered in a routine way by the police. It was pure chance that hacking was revealed. Only a self-regulator that is close to the industry and can uphold standards generally will prevent this.3. The law is costly and slow moving. Proceedings in the courts are slow, inefficient and expensive, whereas a proper regulator can deal with problems quickly, efficiently and cheaply. This is good for everyone. If we used only the law to regulate newspapers then ordinary victims would not have access to a free complaints procedure. The absence of effective self-regulation at least partly explains why we are all now having to pay for big, complex police investigations. These could have been nipped in the bud if there had been a decent ethical framework for journalists.4. The alternative is tougher laws. If we don't have any form of press regulation we will need more and tougher laws. What else would discourage newspapers from, for example, publishing details of suicides that experts say will prompt copycat events? A good code of practice can deal with this if it is effectively enforced. Would we really prefer to pass statutes on such matters? Do we want the police raiding newsrooms or a High Court action every time a reporter sneaks into into a private family memorial event without justification?5. The law is less effective than regulation as a check on a powerful industry. Most other important parts of society – banks, politicians, railways – are subject to scrutiny by the press, and this (alongside the law and regulation) helps keep them virtuous. In this country, however, the press itself is almost free of press scrutiny. Most newspapers maintained a conspiracy of silence on phone hacking and even ganged up on papers that broke ranks. When it came to coverage of the Leveson Inquiry most papers again hid the worst about their own record from their readers.