At first, the signs are subtle: Your computer is slower than usual, something is different about your browser, occasionally you're redirected to an unfamiliar Web site for no apparent reason.

When you finally figure out the problem, you discover that someone has been tracking every keystroke on your keyboard for days while using your PC's resources to maintain a network that researches extraterrestrial life. Adding insult to injury, you find that your eight-year-old son agreed to the whole mess to get some software given away online.

Variations of this scenario have proliferated across the Internet thanks to an emerging breed of opportunistic programs that push the limits on accepted business practices.

With regard to the privacy implications in Australia, Anthea Afaras, privacy lawyer at law firm Deacons, said that it could constitute a breach of privacy unless the parties using the software disclosed, as part of their privacy policy, that personal information may be collected through the software.

"The privacy policy must be made available to the customer, even being provided directly on the site being visited," Afaras said.

Tracking usage, or hits, on a Web site was fine, she said. "But as soon as you have taken somebody's personal details--[that is] they have registered--and you are going to be able to record their activity, then you need to take measures to ensure no breach of privacy," Afaras asserted.

In Australia, the Privacy Act which came into force last December, affects the collection of personal information. Federal Privacy Commissioner Malcolm Crompton said that organisations must make sure that they are collecting information fairly, for example not collecting details by stealth.

"Consumers should beware there's no such thing as a free lunch," Crompton said. "I encourage individuals who have decided to download, install and run freeware or shareware on their PC to look to all the information they have been provided with about the personal information handling processes of the orgnaisation that provided them with the software."

Organisations must use the information for the original purpose or a related purpose within the reasonable expectations of the individual, unless they have the consent of the individual concerned, Crompton said.

He also said that organisations which transferred personal information outside of Australia had to ensure it was handled in a privacy sensitive way, which met standards similar to those established by the Privacy Act.

The issue has also garnered interest abroad, in countries such as the US. "To most consumers, the hard drive is like the home, with the same sense of the sanctity of the home," said Richard Smith, a US-based privacy consultant responsible for revealing some of the earliest online breaches of personal information. "They react to someone snooping in their hard drive the same way they would to someone snooping around their house."

In the US, the Senate Commerce Committee signed off on a bill last month that, among other things, targets companies that include tracking software--known as "adware" or "spyware"--in their products to collect detailed consumer information used for marketing research. Moreover, a group studying consumer Internet privacy for the European Union extended the scope of its inquiry to include music programs, which have been among the most prolific sources for bundled tracking technologies.

"I am opposed to such piggybacking applications. They're dangerous for many reasons," said Andy Oram of technology publisher O'Reilly & Associates, speaking as a member of the activist group Computer Professionals for Social Responsibility. "Users don't really know what is being carried out, and it's possible they might not like the task."

Mike Yamoto contributed to this article.

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