How much information can people learn about you by seeing what you look for on the Internet? Too much, say some people with Internet service from America Online. 

These people should know. AOL put the Internet search records of more than six hundred and fifty thousand people in a public area on part of its Web site. 

The records included every search these users made between March and May of this year. 

The company says the release was an accident. It says the records were meant for researchers. The purpose was to help them study how people use the Internet so search tools can be improved.

To protect privacy, AOL used numbers instead of names to identify the users. But people who saw the records quickly recognized that some users could be identified through the details of their searches.

The New York Times decided to prove it. The newspaper was able to identify one of the users as Thelma Arnold of Georgia. The sixty-two-year-old woman was surprised to get a telephone call from the reporter who found her. But she agreed to a story about her searches. 

Many of them, for example, involved medical conditions. Someone might think she very sick. In fact, in many cases, Thelma Arnold was searching for information to help friends. 

Still, the records from AOL show that Internet searches can tell a lot about what people are thinking. That includes things they might never want others to know they are thinking.

The records could be highly useful to marketers. But some researchers say they will not use them because the information is too personal.

People became angry when they learned that their searches had been made public. AOL took the information off its Web site. The company apologized and called the release "a screw-up."

Some people, however, had already copied the data before AOL removed it. 

The World Privacy Forum and the Electronic Frontier Foundation want the Federal Trade Commission to punish AOL. Both groups say the company violated its privacy agreement with its millions of customers. 

AOL has promised to make changes in the company to help keep records private. The incident has cost three people their jobs, including the researcher who posted the information.