Comment: Coverage of recent Irish Recorded Music Association (Irma) settlements with internet users accused of illegally sharing music online may suggest that Irma is winning its first legal offensive against illegal filesharers. However, it appears that, to date, not all of those targeted by Irma have settled. At least some of those who have held out are likely to progress to court.

Meanwhile, the British Phonographic Industry (BPI) recently filed five cases against filesharers who refused to settle similar claims. A representative of the BPI said that "if people refuse to deal with the evidence against them, then the law must take its course". However, the music industry's confidence in the law delivering satisfactory results needs to be considered in light of potential complications which may threaten their campaign.

Having had some successes against the companies that facilitate filesharing, most notably the US Grokster case, the music industry has recently begun targeting individual users.

The current Irma cases are an example of this new approach.

Irish law provides several civil rights of action to copyright holders in pursuing infringers.

Copyright infringers can also be criminally prosecuted, heavily fined and even jailed. However, although the European Commission is currently proposing further criminal penalties for online copyright infringement, prosecutions are unlikely in the Republic at this stage. Irma's current proceedings are civil rather than criminal.

Traditional defences to copyright actions are of little use to the individual filesharer and cover, for example, academic and journalistic use of copyrighted materials. Nevertheless, Irma could face significant practical and evidential hurdles in presenting its cases, particularly the challenges common to all copyright litigation - cost and complexity. The music industry has deep pockets and an obvious interest to protect, but potential complexities could threaten to unravel their case.

First, evidence could be crucial. Irma was reported to have engaged a US-based company to gather technical evidence concerning illegal filesharers and subsequently obtained a High Court order compelling certain internet service providers (ISPs) to disclose the identities of the filesharers without much difficulty. BREIN, the Dutch equivalent of Irma, also engaged this company but recently lost a similar case against five Dutch ISPs.

Privacy concerns underpinned much of the decision and, although BREIN is unlikely to give up the fight, it was significant that the court was not satisfied that the internet addresses submitted by BREIN were connected to the individuals whose details were sought.

In fact, the Dutch ISPs demonstrated that the US company and BREIN had made numerous errors in making these connections.

It is not unheard of for technical investigations to identify "false positives", like the well-publicised case in the US of a 66-year-old retired schoolteacher whose computer could not run the software which she was accused of using.

The Electronic Frontier Foundation (EFF), an American digital rights group, is helping to defend individuals who claim to have been wrongly identified as illegal filesharers by the US music industry. According to the EFF, the methods used to match usernames with IP addresses are flawed - a contention supported by the BREIN case.

In the Republic, privacy concerns could be revisited should the searching techniques used to identify the filesharers come under scrutiny.

It is also possible that information which comes to light in presenting technical evidence would undermine the ability to detect illegal filesharers in future. If internet discussion boards are anything to go by, certain high-volume Irish filesharers are already one step ahead of the detection game.

Secondly, an individual could claim that the offending files were downloaded by a virus or trojan horse programme. This defence led to the collapse of two child pornography prosecutions in the UK.

One Irish prosecution for child pornography offences collapsed at an early stage as the judge was not satisfied that the accused was in knowing possession of child pornography. An employment case in the UK overruled an internal disciplinary hearing which had found that a police officer sent racist e-mails.

One relevant factor in this decision was that the internal investigation had incorrectly assumed that the technical evidence was beyond challenge.

Thirdly, Irma may have to prove that the person it is suing is responsible for the illegal downloads. Experience from child pornography prosecutions is instructive in that, while the offence is clearly more objectionable, some technical aspects and potential defences are relevant.

Under Irish law, an individual must "knowingly possess" child pornography to be guilty of an offence. This is also the case in the UK, where an accused must be somehow aware of the existence of the pornography to be guilty. Similarly, the liability of those identified by Irma might not be automatic.

Under Irish law, copyright is infringed where a person commits certain acts, or authorises another to do so, without the permission of the copyright owner.

Therefore, the owner of a computer which was used to download illegal songs but who was totally unaware of this, and who did not authorise it, might not be liable for copyright infringement.

This may not be a problem where the relationship between owner and infringer is one of employer and employee, for example, as liability can generally be attributed to the employer.

Where the relationship is that of parent and child, however, novel issues of parental responsibility could arise.

Should these issues be raised as part of a credible defence, Irma's approach could face difficulties.

Philip Nolan is a partner in the commercial department of Mason Hayes & Curran, Solicitors.