Technological changes and personal privacy have been at odds ever since modern notions of privacy emerged more than a century ago. Numerous mechanical devices threaten to make good the prediction that 'what is whispered in the closet shall be proclaimed from the housetops', wrote two Boston lawyers in 1890 in a seminal paper that articulated the modern right to be left alone that is the basis of U.S. privacy law.

Lately, it's been dawning on computer users that our machines say a lot more about us than many of us may realize. Once it was the invention of the camera, the high-speed printer, tabloid newspapers, the telephone. Now it's the computer, mobile camera phones, video surveillance, the always-on Internet, blogging and social network dating sites.

If I am a corporate lawyer by day and a Level 10 Elf by night, I am not sure I want everyone to know my different identities, says David Holtzman, author of a forthcoming book Privacy Lost: How Technology is Endangering your Privacy.

Fast-growing U.S. social network Web site Facebook found out the hard way last week when it introduced a new feature to its member profile pages that allowed users to track their friends' online activities. A vast outpouring of protest among college students forced the company to introduce new privacy features as critics parodied the site as Stalkbook.

CELEBRITIES IN THE MAKING

The 2004 U.S. presidential election turned in part on a furious online debate over whether George W. Bush or John Kerry lied about their war records. But it's not just politicians that are subject to such scrutiny; increasingly we all are. The impulse of everyone from job recruiters to casual acquaintances and first-time daters is to look online and see what the Web says.

Our whole lives are up for review online, Holtzman says. We are all now becoming like politicians, he adds. Only recently, a decade after the Web went commercial, have Internet companies begun to come to grips with how they might use tighter privacy controls in order to expand people's willingness to express themselves.

Now we are turning inward and thinking of blogging as more of a private experience, says Mena Trott, who with her husband, Ben, co-founded Six Apart, the company behind TypePad and LiveJournal, some of the most popular blog services.

Six Apart is set to formally introduce next month a new Web publishing system it calls Vox that includes strong built-in privacy protections to help users share messages and photos while retaining control over who sees particular items.

It's not so much privacy as it is the ability to control one's own publicity. Obscurity isn't enough, Trott says. You need to have the features to say, 'I only want these (specific) people to see this'.

THAT QUEASY ONLINE FEELING

The explosion of self-publishing made possible by easy-to-use blog tools has accentuated the tension between openness and privacy that has existed since the Web was created by academics looking to share research with colleagues online.

Web users have been forced to become always-on extroverts, whether or not everyone is prepared for the consequences of instant celebrity.

When the context of personal information shifts, users find out they really don't have the control they thought, says John Poisson, the founder and chief executive of Tiny Pictures Inc., a San Francisco start-up that has introduced an entirely private online site called Radar.net for sharing photos directly from camera phones with one's friends and family.

A fundamental part of social interaction is an assumption that you and I forget little things about one another over time, Holtzman says. With digitized information you don't forget.

George W. Bush Software Human rights Facebook