Kahle is the founder of an Amazon.com subsidiary, Alexa Internet, which has developed data-collection software now available in a trial version only on the Alexa web site.

• The software looks for patterns shared by many individual shoppers, then aggregates information about the collective navigation of web users.

• It is designed to continuously learn about shopping behavior and improve the quality of information it makes available to consumers.

On Tuesday, Smith filed a formal complaint with the Federal Trade Commission claiming the software was able to gather far more personal data about consumers that Amazon tells consumers it is collecting. In part, he said the software may violate the federal Computer Fraud and Abuse Act and the Electronic Communications Privacy Act.

Kahle said that while some information was unavoidably collected, it wasn't stored permanently and wasn't used to connect Web activity to an individual by name.

However, as one industry analyst noted, what Smith's complaint points out is how easily Web sites can collect information most people would consider personal. Web sites are becoming huge data bases that gather personal information and use it to tailor content and advertising to individual consumers based on such items as address, gender, age and wealth.

"I respect Brewster's ethics," Smith said, "but what happens when he leaves? There are no legal protections on the Web."

Source: John Markoff, "Bitter Debate on Privacy Divides Two Experts," New York Times, December 30, 1999.