Washington

SETI@home users beware — aiding the quest for extraterrestrial intelligence could land you on the wrong side of the law.

Computer administrator David McOwen faces prosecution by the state of Georgia after he downloaded distributed-computing software — which divides time-consuming computing problems among many machines — onto computers at DeKalb Technical College, where he worked two years ago.

Millions of users have installed the distributed SETI@home software, which analyses radio signals from space to search for signals from extraterrestrial life. McOwen had downloaded software from distributed.net, a website that specializes in software for tackling mathematical problems such as encryption.

McOwen, who is expected to face trial later this month, has been charged under Georgia's computer-hacking law. This law prohibits altering or interfering with computer data “with knowledge that such use is without authority”. Similar laws exist in other states.

But David Joyner, McOwen's lawyer, says that his client did not violate any clear written policies. “It's inherent in his position to have the authority to run whatever program he felt like he needed to run,” he says. Joyner adds that students at the college downloaded SETI@home software without being arrested.

The Electronic Frontier Foundation, a San Francisco-based group that campaigns on civil-liberty issues related to information technology, says that the case — the first of its kind — has worrying implications. “We've had a number of people, primarily in the mathematical world, tell us this is scary, because there are clearly good things that can be done with distributed software,” says Lee Tien, a lawyer for the organization.

One popular program, the Great Internet Mersenne Prime Search, lets users search for prime numbers of the form 2n − 1. A record-breaking four-million-digit prime number was found last November. Researchers at the University of Oxford are using a distributed computing project to screen small molecules for promising leukaemia drug candidates, and have signed up more than a million users since the project was launched last April.

Dave McNett, president and co-founder of distributed.net, denies that distributed computing projects are in danger. “I think this has raised awareness that you shouldn't run software on machines you don't own without permission,” he says. “That has always been our policy.”