Lord Steyn said,
‘The starting point is the right of freedom of expression. In a democracy it is the primary right: without it an effective rule of law is not possible. Nevertheless, freedom of expression is not an absolute right. Sometimes it must yield to other cogent social interests…
Freedom of expression is, of course, intrinsically important: it is valued for its own sake. But it is well recognised that it is also instrumentally important. It serves a number of broad objectives. First, it promotes the self-fulfilment of individuals in society. Secondly, in the famous words of Holmes J. (echoing John Stuart Mill), “the best test of truth is the power of the thought to get itself accepted in the competition of the market:” Abrams v. United States (1919) 250 U.S. 616 , 630, per Holmes J. (dissenting). Thirdly, freedom of speech is the lifeblood of democracy. The free flow of information and ideas informs political debate. It is a safety valve: people are more ready to accept decisions that go against them if they can in principle seek to influence them. It acts as a brake on the abuse of power by public officials. It facilitates the exposure of errors in the governance and administration of justice of the country… It is this last interest which is engaged in the present case. The applicants argue that in their cases the criminal justice system has failed, and that they have been wrongly convicted. They seek with the assistance of journalists, who have the resources to do the necessary investigations, to make public the wrongs which they allegedly suffered.
The value of free speech in a particular case must be measured in specifics. Not all types of speech have an equal value.’
[Edited and formatted for ease of reading.] You can find this case on Westlaw.