Key Points:

A legal move believed to be a world first has opened the way for New Zealanders to be served legal documents through their Facebook sites.

Canberra lawyer Mark McCormack expects other courts will follow his lead after he used the internet to find a couple who had defaulted on a six-figure loan and serve them with a default judgment.

His action could easily be repeated on this side of the Tasman.

Crown Solicitor Simon Moore, SC, said using internet sites such as Facebook made perfect sense.

"In civil courts, there has always been the facility to apply for substituted service in cases where a defendant may be difficult to find or evidence suggests they are deliberately evading documents being served on them."

Courts usually leave legal documents at a defendant's last known address or somewhere they know family members are.

Mr Moore said the Facebook option was a novel way of serving documents and probably an effective option of bringing court action to someone's attention.

"I suspect it is a first and can't see why it can't be followed here," he said.

But it was unlikely to be used to serve papers related to criminal cases, except for minor cases.

Auckland District Law Society president Keith Berman said a traditional way of serving legal documents was through a public notice in the classified section of newspapers.

"There's no reason at all why the courts couldn't get more modern," he said.

He did not know if legal documents had been served by email but "wouldn't be surprised if it has been done".

The Australian Capital Territory Supreme Court approved lawyer Mark McCormack's application on Friday to use Facebook to serve the legally binding documents after several failed attempts to contact the couple at the house and by email.

Australian courts have given permission in the past for people to be served via email and text messages when it was not possible to serve them in person.

The lender's application to take back the house in the capital, Canberra, was approved on Oct. 3 after the couple failed to appear in court. The lender was then required to serve the so-called default judgment on the couple before it could seize the property.

"It's somewhat novel, however we do see it as a valid method of bringing the matter to the attention of the defendant," said McCormack, who represents a mortgage lender.

Facebook has become a wildly popular online hangout, attracting more than 140 million users worldwide since it launched in 2004. Facebook friends can "poke" or "superpoke" each other - terms for giving someone a playful nudge.

Lawyer and computer forensic expert Seamus Byrne said he was aware of only one similar case in Australia. A Queensland state District Court judge ruled in April against documents being served by Facebook because the option of contacting a person via a post office box had not yet been exhausted.

In the latest ruling, Master David Harper insisted that the documents be attached to a private email sent via Facebook that could not be seen by others visiting the pages.

McCormack said he and a colleague found the woman's Facebook page using personal details that she had given the lender including her birth date and email address. The man was listed on her page as a friend. Neither had imposed security options that deny strangers access to their pages.

McCormack said he did not bother searching for the couple through any other social networking sites.

"It's one of those occasions where you feel most at home with what you know and I myself have a Facebook account," McCormack said.

Mr McCormack, a keen Facebook user, said using the popular social networking site to contact people who flee was the logical "next step".

"I think the courts will continue to adopt it on a case-by-case basis," he said.

They would need only to assure themselves that it was reasonably likely to bring the court's decision to the attention of the parties concerned.

Mr McCormack said his legal firm, Meyer Vandenberg Lawyers, hadn't been able to find any other examples of Facebook being used to serve a court judgment.

The lawyer is acting for a lending institution which loaned the Canberra couple more than A$100,000 ($122,000).

When they defaulted and couldn't be found at their listed residence, he had to get creative.

The lawyer obtained a default judgment in the couple's absence and was able to convince the court to serve it via Facebook.

The fact the defaulters' Facebook accounts included their names, dates of birth and listed each other as "friends" persuaded the court it had the right people in its sights.

This year, lawyers acting for the Bulldogs NRL club served New Zealand-born player Sonny Bill Williams with a subpoena by mobile phone text message.

Williams was in Europe after defecting to French rugby club Toulon.