The full glare of a public hearing enables everyone to know that justice is being administered fairly. It allows the press and the public to report on, to scrutinise, and to comment upon, the workings of the law.
Every person facing a criminal charge is entitled to a fair trial, so commentary giving rise to a substantial risk of serious prejudice to an active trial can amount to contempt of court.
There can be a fine line between commenting on a trial, and prejudicing it. This line was certainly brought into focus at the conclusion of the Jobstown trial.
Not only had there been widespread reportage by broadcast and print media, but there was also a great deal of coverage online, including a social media campaign.
The right to comment on the administration of justice, and the rules of contempt that set the limits to that right, apply to everyone equally, in traditional media and on social media alike.
So, the rules are the same for anyone who writes a commentary, whether that is published by a newspaper or on a blog.
The key question is always whether there is a substantial risk to the fairness of the trial, and that must always be judged on the facts of each particular broadcast or publication.
On the one hand, a headline on TV or in a national daily newspaper will have far greater reach and impact than exactly the same words in a tweet.
On the other hand, if an unfair or inaccurate online report was to go viral, and spread rapidly and widely through social media, such that it quite quickly had 500,000 unique interactions (such as comments, likes, retweets, shares or forwards), then it too could pose a substantial risk to the fairness of the trial.
Moreover, widespread coverage that raised a substantial risk of influencing a jury to deliver a particular verdict would be contempt, whether it was conducted over the airways, through the pages of a magazine, or online.
It is frequently the case that the law takes a while to catch up with technology.
But as the law understands the reach and limitations of social media, so the rules on contempt can be properly applied to online commentary.
In the context of controversial trials in the UK, the Attorney General often issues reminders to "editors, publishers and social media users" that proceedings are active and that the contempt of court rules apply. It may not be long before the DPP here issues similar advice.
In 1994 the Law Reform Commission published a report recommending various reforms to the law on contempt. It is now looking once again at these issues.
Perhaps the controversy over the social media coverage of the Jobstown trial will ensure that these proposals form the basis of much-needed legislation.
If so, the scope of contempt, online and offline, will be clarified. The accused's right to a fair trial will be protected. And the principle of open justice will be properly respected.
Dr Eoin O'Dell is an Associate Professor of Law, Trinity College Dublin. He blogs at http://www.cearta.ie and tweets @cearta