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Caller ID

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Computer Professionals for Social Responsibility

Caller ID

Caller ID is the name usually used by telephone companies to describe a service in which telephones can be made to report the number of the calling party. CPSR prefers the name Calling Number ID (CNID) for the service, since it actually identifies the number of the phone being used to call, rather than the caller per se.

CNID is promoted as a service that gives individuals greater ability to screen unwanted calls. However, because many incoming numbers are unfamiliar to call recipients, CNID is less useful for screening out unwanted calls than an answering machine is. When an incoming call shows a number you don't recognize, do you answer it or not? It might be a telemarketer or it might be a friend or relative calling from an unfamiliar phone.

The important commercial advantage for the service, however, is that it allows businesses to collect caller numbers and thereby create telephone databases that will be used to increase telemarketing. CNID also raises significant privacy concerns, particularly for people who are, for example, calling a crisis line where the call is supposed to be anonymous.

CPSR is on record as preferring alternatives to CNID such as allowing callers to key in or speak an identifying name. Such alternatives provide better information for screening calls while not giving telemarketers - or companies that sell phone numbers to telemarketers - your phone number. At a minimum, CPSR believes that any CNID system must allow callers to block the transmission of their phone number on both a per-line and per-call basis, with per-line (aka "constant") blocking as the default unless the telephone customer requests otherwise.

History of CPSR's Involvement in the CNID Issue

In the late 1980s and early 1990s, state Public Utility Commissions (PUCs) across the U.S. were trying to decide whether to approve telephone company's requests to offer CNID service. After CPSR raised concerns in articles published in the CPSR Newsletter and in newspapers around the U.S., we got directly involved in PUC proceedings in several states.

The decisions of state PUCs varied, but some agreed with CPSR's analysis that CNID as proposed by the phone companies - with no ability to block one's number or with blocking available only on a per-call basis - violates caller's privacy. In California for example, the hearing officer recommended to the California PUC that CNID be disallowed. The Commission decided to allow it, but with the requirement that telephone numbers would be blocked by default unless the caller indicated that the number could be transmitted. Faced with such a strong restriction, telephone companies declined to offer CNID. In Oregon, CPSR's participation in the PUC hearings led to important privacy concessions by the phone company, so the service was approved. In Massachusetts, CPSR's recommendation was adopted: the service was approved with numbers being blocked by default unless the caller indicated otherwise.

Faced with strong privacy restrictions on CNID in many states, telephone companies petitioned the Federal Communications Commission (FCC) to issue rules on CNID that would apply nationwide. CPSR submitted written arguments to the FCC. Virtually ignoring public input, the FCC mandated per-call blocking as the default nationwide, overruling many state decisions. Several states appealed, with support from CPSR. The FCC denied the appeals, clearing the way for telephone companies to offer CNID with weak privacy protections nationwide. That is what we have today.

For a more comprehensive capsule history of CPSR work on the CNID issues, see the article by Marc Rotenberg in the April 1992 issue of Communications of the ACM.

CPSR Documents on CNID

(Note: These are historical documents, provided for the record, but not updated)

Government Documents on CNID

  • Opinion of the Supreme Court of Pennsylvania - Decision requiring strict limitations on Caller ID service, March 18, 1992.

  • S.B. 652 (1992) - Old bill from 1992 Congressional session to protect the privacy of telephone users by amending section 3121 of title 18, United States Code, March 13, 1991.

  • H.R. 1305 (1991) - Old bill from 1991 Congressional session to amend the Communications Act of 1934 to protect the privacy rights of telephone subscribers, March 6, 1991.

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Archived CPSR Information
Created before October 2004

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