Telephone Caller Identification (Caller ID)

Telephone Caller Identification (Caller ID)

Caller identification, or caller ID, permits the receiver of a call to identify the caller's location. Available since the early 1990s, it has enhanced the sense of privacy enjoyed by persons in their homes, and has also greatly reduced the number of prank calls, as well as calls made with threatening or criminal intent. Ambivalence about the privacy ramifications of caller ID, however, has made the state of California slow to accept the technology.

In 1985, the Los Angeles Times ran a report on an ultra-chic security products boutique whose customers included the late Shah of Iran and the makers of the James Bond movies. Counter Spy Shop (CSS) in Washington, D.C., sold a telephone voice scrambler for $14,000, yet, as the newspaper article noted, "What CSS cannot do, despite numerous requests from potential customers, is pinpoint the place of origin of an incoming call." To do so "would require access to the telephone company's computers, something that even CSS lacks."

Within half a decade, telephone companies had made such technology available, for a small fee, to all customers. A caller ID box, or a caller ID unit built into a phone, simply reads the computerized information for the incoming call, assuming it is coming from a listed number. Calls from an unlisted number register as "Unknown Caller" or "Private Caller." Available on internal private branch exchange (PBX) telephone systems during the 1980s, caller ID gained use by businesses offering toll-free numbers in 1988. It became available to residential customers in 1989, and by 2001, 43% of homes nationwide had caller ID.

An exception was California, where privacy concerns had kept the service away for many years. Before telephone companies could bring caller ID into the state, they had to spend $34 million on an advertising campaign to tell callers that the service would make their phone numbers visible, and that this could be used to obtain the caller's address. By 2001, four years after the introduction of caller ID in the state, about one quarter of Californians used the service.



Crabb, Peter B. "The Use of Answering Machines and Caller ID to Regulate Home Privacy." Environment and Behavior 31, no. 5 (September 1999): 657–70.

Kupperschmid, David. "James Bond 'Supplier' Has the Cure for Whatever Is Bugging You." Los Angeles Times. (April 26, 1985): 2.

MacSweeney, Greg. "Caller ID with a Kick." Insurance & Technology 25, no. 10 (October 2000): 30–35.

Mehta, Stephanie N. "Playing Hide-and-Seek by Telephone—Phone Companies Are Arming Both Sides in the Battle to Screen Unwanted Callers." Wall Street Journal. (December 13, 1999): B1.

"Tech 101: Hollywood's Caller ID Hang-Up." Los Angeles Times. (May 24, 2001): T1.


Johnson, Jeff. Caller Identification: More Privacy or Less?—Winter-Spring 1990 (Volume 8, Number 2). Computer Professionals for Social Responsibility. < > (April 2, 2003).


Privacy: Legal and Ethical Issues
Telephone Scrambler

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