Comment: The long awaited Defamation Bill, which was presented to Cabinet on Wednesday, may not immediately excite the interest of those who are not in the publishing business. But in reality, the increasing use of the internet and, in particular, blog sites (personal weblogs) means that it is now much more likely that any one of us could be defamed or be responsible for defaming someone.

Internet defamation can have a much more damaging effect than traditional forms of libel. Not only is the potential audience for internet libel massive, but search engines provide an environment where a derogatory mention of a person on a blog can be highlighted within seconds and remain available for public viewing for years to come.

Equally, there is a tendency to regard postings on the internet as transient things; we may view a contribution to a chat room as an informal opportunity to sound off, not realising the global consequences for the person who happens to be the butt of our ire. One comment might lead to a string of comments, which may in turn be picked up by other blog sites or discussion boards, leading to what amounts to an aggressive campaign targeted at the unfortunate subject of the criticism.

Blogging is becoming big business. It is used by the senior executives of major companies such as General Motors and Boeing to communicate directly with customers and to combat negative publicity. These executives tend to publish under corporately mandated guidelines, which mean it is highly unlikely that they will defame anyone.

However, blogging's real growth is coming from the huge numbers of individuals who regularly post comments on their own blogs or on other blogs about their daily lives and interests.

While the vast majority of this kind of activity is innocuous, some bloggers seem to feel that because they are posting on the internet they are free from any legal consequences for what they write and, as a result, are engaging in defamatory abuse of individuals and companies. This feeling of invulnerability can often be heightened if the blogger is hiding behind the apparent anonymity provided by code names and abstract e-mail addresses.

What bloggers should remember before they post is that the same principles apply to internet libel as to libel in books or newspapers, and they should not assume that they can defame people online without consequences. A good rule of thumb is that bloggers shouldn't post anything online that they wouldn't be happy to write in a signed letter or put on a public notice board with their name attached to it.

Of course, in the huge, complex world of the web, tracing the writer of a defamatory comment is a lot more difficult than finding an article in a newspaper.

However, it is possible to trace offending bloggers with a bit of perseverance and lawyers often find that a formal complaint to the website host or internet service provider (ISP) and to the administrator of the website will lead to the removal of the offending material, without the need for litigation.

So far, no cases like this have reached trial in the Irish courts, but the increasing number of cases arising in other jurisdictions means it is probably only a matter of time before the courts here have to address this issue.

In 2005, the UK high court granted an order requiring the website Motley Fool to disclose the computer ID and e-mail address of a person who had posted defamatory remarks about Terry Smith on the site using the code name "analyser71".

Smith, a city analyst whose business was seriously affected by the libel, subsequently sued the offending blogger and recovered substantial damages and costs against him. He recently settled a related action against the Financial Times, which had published the allegations, for £300,000 (€433,000) plus costs.

Also in 2005, Ryanair secured an interim injunction in the Irish courts preventing the Ryanair European Pilots Association website from deleting or destroying material capable of identifying a contributor to the website, who had posted comments under the code name Leo Hairy Camel.

If a person has been defamed on the internet they can take steps to protect their reputation by submitting a legal complaint to the blog/website and the website host or ISP. Unlike their US counterparts, Irish ISPs do not enjoy any immunity under Irish law at present and generally take a constructive approach if pressed, although they will often seek to deny liability initially.

Where material that has been posted is plainly defamatory it is usually possible either to persuade them to close down the website or remove the offending content.

The Defamation Bill is expected to leave scope for companies like ISPs to be held liable for defamation, but there needs to be a serious debate about the extent to which we should make it harder for someone defamed on the internet to remove offensive material or close down websites.

For most people affected by internet libel, the priority is action rather than compensation. The stick that forces ISPs to act as the law currently stands is the potential for litigation. If that is diluted, people defamed on the internet may be left much worse off.

Karyn Harty is a partner and head of defamation in McCann FitzGerald's litigation department. This article does not constitute legal advice.