Police sergeant John Ellsworth has sparked a privacy debate in the US that has prompted many to reconsider who can access their e-mail.

Mr Ellsworth is locked in a legal fight with Yahoo! after his son, L/Cpl Justin Ellsworth, a US marine serving in Falluja, was killed by a roadside bomb.

L/Cpl Ellsworth was 20 when he died at the beginning of November, less than two months after arriving in Iraq. During that short spell of duty, the young soldier had spent much of his spare time e-mailing his folks back home through Yahoo! webmail.

"He was keeping a journal of sorts to put together for future history," John Ellsworth told BBC News. "He wanted to make sure that his generation, as well as following generations, have actual words from somebody who was there."

They are attempting, in effect, by contract, to extinguish a property right to the contents in the account Solicitor Leigh Ellis

But Mr Ellsworth Snr was shocked when Yahoo! turned down a request to release his dead son's e-mails, on the basis of privacy.

Recognising the emotions involved, Yahoo! says it must nevertheless honour the terms of service which all 40 million US Yahoo! account holders must agree to. These state that survivors have no rights to the e-mail accounts of the deceased. Yahoo! accounts are deactivated after 90 days if they have not been used.

Other big players in the webmail market, such as AOL and Hotmail, have procedures for transferring e-mail accounts of the deceased to next of kin. Yahoo! UK, meanwhile, has less strict privacy terms than its US counterpart.

But Mr Ellsworth is not about to give up. Having spent weeks trying, unsuccessfully, to crack the password to his son's account, he has taken his story to the media, appearing on US network TV. He has also enlisted lawyers to fight his corner.

The case has split public opinion, with some urging Yahoo! to make a compassionate exception, while privacy activists believe there should be no exceptions.

A debate hosted by the website ZDnet illustrates the broad spectrum of feeling.

Yahoo's terms: The source of the debate

"The man is devastated at the prospect of his son's memories, what essentially could be his son's last written words, being obliterated forever. Just let him see it," writes one contributor.

Another talks of a family member who committed suicide: "There are many questions that remain unanswered for us and yet, I know that she would not have wanted us to access her e-mail account after her death."

So who does own your e-mail after you die?

Solicitor and technology expert Leigh Ellis, of Kaltons Technology Specialists, says in English law at least, the copyright vesting in e-mails, like other possessions, is included in the estate of the deceased. In which case the copyright as property, would pass to the executor.

The fact that this is webmail, and so is contained on disks owned by Yahoo!, makes no difference. The contents of the e-mails remain the property of those who wrote them.

But the nub of the Ellsworth case appears to rest on Yahoo's clause which states "You agree that your Yahoo! account is non-transferable and any rights to your... contents... terminate upon your death."

"They are attempting, in effect, by contract, to extinguish a property right to the contents in the account," says Mr Ellis.

Police access

However, another clause in the same Yahoo! terms appears to give some room for manoeuvre. It states that "Yahoo! may... disclose your... content if required to do so by law or in a good faith..."

The term is clearly drafted to give the police rights to access an account.

"Strictly speaking, anyone trying to access the e-mails of the deceased is fighting an uphill struggle against these clauses," says Mr Ellis. But given the emotions of a case such as Mr Ellsworth's, "Yahoo! may in the end relent to the adverse publicity arising from their resistance and the particular circumstances of the case.

"Defending non-disclosure of information after a person has passed away on the basis of privacy would present some difficulty in the UK as the Data Protection Act would not apply to the information."