The legal system is often accused of lagging behind the technological curve – indeed, it is only a couple of years since a high court judge made headlines by saying: "I don't really understand what a website is." He later said that the remarks were taken out of context.

Once in a while, however, the courts get ahead of the curve. Eight years ago, for example, America took the pioneering step of making every court document available online to the public. The grand plan was, understandably, hailed by transparency advocates and freedom of information campaigners.

The centrepiece of the effort pushed through by the US Congress, from early 2001, was web access to Pacer, the Public Access to Court Electronic Records scheme. This had provided electronic access to court records since 1988, but via a network of terminals largely limited to libraries and official buildings.

Legal minefield

The Pacer website is a vast database of PDF files for download over the web from the country's many district, appellate and bankruptcy courts, among others.

But while the sentiment behind the system is admirable, even Pacer's biggest fans admit that it is far from perfect.

For starters, the highly atomised nature of the US court system mean that documents are often hard to find. Also, users cannot access documents without handing over their identity and credit card number, and the system itself is based around a clunky, arcane-looking and labyrinthine database aimed largely at lawyers and experts. And then, perhaps most importantly, there is cost.

Users of Pacer are charged eight cents (around 4.8p) a page. There are price limitations – a ceiling of $2.40 a download, for example – but case documents are often split into batches and can run to hundreds of pages overall. And the complexities of court filings mean that lay users can rarely be sure that the files they are paying for will deliver the information they seek.

That's where a team from Princeton University, in New Jersey, decided to step in. Their Recap tool, as the name suggests, aims to turn Pacer on its head: by making legal documents more easily available, and dramatically reducing the cost.

"All of the stuff in Pacer is, essentially, part of the law of the land," says Harlan Yu, a Princeton PhD student and one of the trio behind Recap. "Our nation is governed by laws, and we feel like the law should be accessible to all. And being accessible, in this day and age, means that the law should be online where it's most accessible to citizens in a way that is free."

The system that Yu developed, along with his colleague Tim Lee and Stephen Schultze, an academic who was working at Harvard's Berkman Center for the Internet and Society at the time, is an ingenious twist on peer-to-peer networking.

"We were talking about ways we could get access to these documents in bulk," he says. "We figured there were probably ways you can automate the process."

The resulting system is an ingenious twist on peer to peer networking. Users download a plug-in for the Firefox browser. When they browse for a legal filing, the system checks whether another user has requested it. If it has never been purchased, the user pays – and the file is automatically sent to join a library held by the Internet Archive. If another Recap user has paid in the past, the archive copy can be downloaded free. The system may look familiar to fans of the original Napster.

But there are no questions of legality with Recap. Most court files are in the public domain – meaning that anyone who takes them has the right to publish them anywhere.

"Once somebody extracts a document from Pacer and actually pays for it, you can post it on a blog, share it with your friends – you can do whatever you want with it," says Yu.

Since the system launched in August, legal circles have been buzzing with support for the idea.

"We've gotten a good response from lawyers who use the system often and certainly from academics who want to do longitudinal studies about the courts," says Yu. "We've gotten very positive feedback … from investigative journalists and non-profits who do a lot of Pacer work and pay a lot of money to Pacer. This allows them to do more of that without worrying too much about the cost."

Reaction was so encouraging that Schultze has now joined the Princeton team and they are planning to expand the scheme, though they admit there are important privacy implications to work through before all documents should be automatically exposed to the public.

Paywall pains

But what about Pacer itself? Does diminishing the paywall destroy its funding? Apparently not.

In 2006, the system increased the original seven cent charge — and has since built up a cash surplus of more than $150m (£89.7m). Yu says that much of the organisation's budget is spent on courtroom technology not directly related to public access, while politicians including the former vice presidential candidate Joe Lieberman have publicly questioned how the scheme has built up such a surplus, and asked why it still charges.

For its part, Pacer says it is not too troubled by the project, though it has warned courts not to encourage use of Recap, and suggested that it was a security risk because it could "possibly be modified for benign or malicious purposes".

Recap is not the first to liberate these documents from behind the paywall. There are websites such as public.resource.org, FreeCourtDockets.com and Justia.com that republish documents from Pacer. Others, such as Lexis Nexis, charge for a service that includes re-publication of Pacer documents. It has automated what was usually a manual process of sharing.

For advocates, the bigger question is whether Pacer objects: opening access to legal documents is an important part of expanding free data and free information. After all, it was Thomas Jefferson – who made his living practicing the law, among other things – who said that "information is the currency of democracy".