Bell Atlantic, the telephone company that routes Harvard's telephone calls, says it is similarly close-mouthed about its customers' personal information.

"Years ago, we offered our directory lists for sale, and gave our customers the option of opting out," says Bell Atlantic spokesperson Joel H. Johnson. "So many people opted out that we realized this was not something we wanted to be doing."

Indeed, the experience of other schools suggests phone books are the likely source.

Tracy L. Riddle, associate dean of students at Augustana College, a Lutheran college in South Dakota, says a company called Career Horizons flooded their campus with mailings offering $100 to the first student to provide it with a student telephone directory.

Riddle doesn't know which student in this school of about 1,000 sold the directory, but soon after the offer, student were flooded with eight to 10 calls a day hawking everything from cars to credit cards.

"I've never seen students so passionate about anything," she says. "Part of it is that they're getting calls at seven in the morning and as late as 11 at night. It's just a very big inconvenience."

Riddle says there was no disclaimer on the telephone book warning against its misuse