Does the average person mind when, after having a prescription filled at the pharmacist, he or she starts getting related junk mail from drug companies to which the pharmacy has passed along his or her name, address and medical condition? Are such customers likely to be pleased at the convenience — as the pioneers of this new form of medical marketing insist they ought to be — or are they likelier to bristle at the implied violation of their privacy? Anyone who finds this a difficult question ought to glean a big, broad hint at the answer from the fierce consumer reaction to a report in this newspaper Sunday that several large area pharmacies, including those at the Giant Food Inc. and CVS chains, have entered into such arrangements with a Massachusetts-based company called Elensys. Today, in full-page ads and other formats, Giant announces it will stop providing such information — reacting to what spokespeople said had been a flood of calls from angry consumers.

And what were pharmacists — next door to doctors in their access to privileged, personal knowledge about people’s ailments — doing marketing such information in the first place? The answer casts some light on the strange tensions being set up everywhere by the financial possibilities — one might better call them temptations — of the so-called "information economy," in which information about one’s customers and their needs has become a vast new resource to be mined. It shouldn’t surprise anyone that consumers feel more strongly about their medical prescriptions than they do about the great amounts of other information now routinely collected from every financial transaction, whether it’s traveling, shopping or browsing the Internet. But information about people’s preferences — meaning the sorts of things they are likely to do, or read or buy — is by far the most valuable of the various sorts of information now being briskly harvested and traded on all sides. Any company that collects such information in the ordinary course of business is sitting on a gold mine — and can be expected to act on that fact in the absence of specific, spelled-out public limits.

To what extent should people’s needs be allowed to be treated this way, as some sort of naturally occurring resource available to anyone who can grab it? The outcry over drug prescriptions suggests one such limit. While some forms of sensitive information, such as credit information, are now protected, the sheer variety of types of medical data have made progress slow on protecting them.

Prescription information falls near the line between purely medical data and commercial information, but as the reaction makes clear, that line has been crossed. Besides being inherently more sensitive and personal than information about shopping choices, prescriptions are also in a real sense less optional: Nobody "chooses" to have a particular ailment or to release the information about that ailment into the wider data stream of junk mail.

The arrangements with Elensys, which contracts to manage pharmacists’ data about patients and to make selected bits of it available so drug companies can send potential patients "educational material" about their inferred ailments, are just ingenious enough to focus people’s attention on where they want that line drawn.