Anyone making long drives this summer will notice a new dimension to contemporary inequality: a widening gap between the users of automatic toil-paying devices and those who pay cash. The E-ZPass system, as it is called on the East Coast, seemed like idle gadgetry when it was introduced a decade ago. Drivers who acquired the passes had to nose their way across traffic to reach specially equipped tollbooths—and slow to a crawl while the machinery worked its magic. But now the sensors are sophisticated enough for you to whiz past them. As more lanes are dedicated to E-ZPass, lines lengthen for the saps paying cash. E-ZPass is one of many innovations that give you the option of trading a bit of privacy for a load of convenience. You can get deep discounts by ordering your books from Amazon.com or joining a supermarket 'club.' In return, you surrender information about your purchasing habits. Some people see a bait-and-switch here. Over time, the data you are required to hand over become more and more personal, and such handovers cease to be optional. Neato data gathering is making society less free and less human. The people who issue such warnings—whether you call them paranoids or libertarians—are among those you see stuck in the rippling heat, 73 cars away from the 'Cash Only' sign at the Tappan Zee Bridge. Paying your tolls electronically raises two worries. The first is that personal information will be used illegitimately. The computer system to which you have surrendered your payment information also records data about your movements and habits. It can be hacked into. Earlier this year, as many as half a million customers had their identities 'compromised' by cyber-break-ins at Seisint and ChoicePoint, two companies that gather consumer records. The second worry is that personal information will be used legitimately—that the government will expand its reach into your life without passing any law, and without even meaning you any harm. Recent debate in Britain over a proposed 'national road-charging scheme'—which was a national preoccupation until the London Tube bombings—shows how this might work. Alistair Darling, the transport secretary, wants to ease traffic and substitute user fees for excise and gas taxes. Excellent goals, all. But Darling plans to achieve them by tracking, to the last meter, every journey made by every car in the country. It seems that this can readily be done by marrying global positioning systems (with which many new cars are fitted) with tollbooth scanners. The potential applications multiply: what if state policemen in the United States rigged E-ZPass machines to calculate average highway speeds between toll plazas—something easily doable with today's machinery—and to automatically ticket cars that exceed 65 m.p.h.? There is a case to be made that only a citizenry of spoiled brats would fret over such things. Come on, this argument runs, anyone who owns an anti-car-theft device—Lo Jack in the United States or NavTrak in Britain—is using radio tracking to make a privileged claim on government services. If your LoJack-equipped Porsche is stolen, you can call the local police department and say, in effect, 'Go fetch.' Stolen cars with such devices are almost always recovered. Car theft has fallen precipitously, which benefits us all. For some time, the United States has required commercial trucks to register their mileage and routes. Last year, Germany initiated a new, more efficient G.P.S.-based truck-tracking system that seems intrusion-proof. Authorities dis card the records after three months, which means they can't use them to arrest criminal truckers or dun deadbeat ones. Can such forbearance last? In Germany, where history makes lax surveillance seem the lesser evil. yes. But not in the United States. Since the Warren Court, voters have. again and again, risen up against any libertarian trammeling of government in its fight against c