Telephone companies say they put a dent in this 'shoulder surfing' by furnishing pay phones with automatic card readers as well as plastic shields and other measures to obstruct the view of potential thieves.

"Shoulder surfing" is the term for someone who stands behind a customer and looks over his or her shoulder, sometimes using binoculars, to discover the customer's secret code.

Shoulder surfing, the stealing of passwords by watching users sign on to systems at their terminals, is generally a ploy of employees. But Parker tells of a more ingenious variation of the technique. Juvenile computer hackers invaded the financial district of a major southern city by spying with binoculars on employees in adjacent buildings who were working at their computers and terminals. The youths were able to pick up passwords and log-on protocols t gain access to systems.