Hey CLEC, who called me?

April 13, 2012 6:00 AM

Did telephone companies routinely keep records of *incoming* calls in the pre cellphone days?

Asking for my wife who is writing a story and an issue is whether or not in 1990 (when story takes place) a phone company in the US (specifically New York, so figure Nynex in those days) would routinely keep records of a subscriber's incoming calls, like from say, a pay phone, if there was no court order or no call tracing involved.

In pre-cell days when you routinely got charged for making calls but not recieving them, your bill wouldn't show calls you got. But what if you had to prove so-and-so called you, and say so-and-so called from a pay phone. I know they had caller ID in those days, but would that info be available, say if a lawyer asked for it? Or since they didn't need it for billing, did they bother to record it?

Tried Google &c, but I haven't come up with anything specifically relating to my question. Answers range from tracing calls, to caller ID, etc. but not if Nynex could tell me who called me at 6:27PM on June 24th, 1989 if a lawyer sued them to get that info.

Anyone who perhaps worked for a phone company in those days?

posted by xetere to technology (8 answers total)

Perhaps you could ask the person who gave this answer about LUDS on Law & Order.
posted by Mercaptan at 6:18 AM on April 13, 2012

Not a phone company employee, but I think the answer is 'no,' plus your phone bill only listed your outgoing long-distance calls. With a court order, the phone company could probably produce a list of your outgoing local calls, but not incoming. And Caller ID was far less common than it is now. The majority of landline call plans covered unlimited local usage, and didn't charge separately for each outgoing local call, but even with the few pay-per-outgoing-call plans, there was no need to keep track of incoming calls for billing purposes.
posted by easily confused at 6:19 AM on April 13, 2012

Asking for my wife who is writing a story and an issue is whether or not in 1990 (when story takes place) a phone company in the US (specifically New York, so figure Nynex in those days) would routinely keep records of a subscriber's incoming calls, like from say, a pay phone, if there was no court order or no call tracing involved.

Unless your theoretical reader worked for the phone company in 1990, it's pretty unlikely they're going to know, either. It's plausible enough that they would-- just do whatever works for the story.
posted by empath at 6:57 AM on April 13, 2012 [1 favorite]

I can tell you for sure that we do now, though, and have for at least 10 years. (I work for a clec).
posted by empath at 6:58 AM on April 13, 2012

I can't point you to a technical reference, but I can almost assure you that those records were kept.

Also, law enforcement can get dialed number records without a court order (only the conversation itself is protected, not the fact that the conversation took place).
posted by NotMyselfRightNow at 7:18 AM on April 13, 2012

They probably did, so they could make money.

In the US, the economy of transmitting telephone calls relied on the creator telephone company of a call to pay the receiver ("terminator") telephone company for the call. If I were running a telephone company, I would definitely have a large incentive to having records of how I terminated calls so I can bill the other telcos. I'd want that some of that information for several months, to make sure no disputes arise in courts that I can't crush with hard data.

Now, they could aggregate and discard personal information about the call, but unless space was a concern, it wasn't necessary.
posted by cmiller at 8:43 AM on April 13, 2012

Unless your theoretical reader worked for the phone company in 1990, it's pretty unlikely they're going to know, either. It's plausible enough that they would-- just do whatever works for the story.

I was born in 1983. Obviously I didn't work for the phone company in 1990. I would be bugged by this question, because I remember that you didn't have to pay for incoming calls. I think people roughly my age or older are likely to know this.

Then again, I'm not sure if I'd notice that this detail was a bit incongruous if it were buried in a story. Since you're asking I'm saying it doesn't ring true for me, but if it works in context I'd probably skip over it.
posted by madcaptenor at 9:03 AM on April 13, 2012

I can practically guarantee that you will get a technically correct answer, probably sooner than you think, by asking the TELECOM digest (aka comp.dcom.telecom, but you need to sign in to Google Groups now). You might even be able to search it and find the answer there, but just go ahead and ask.

I'll just say this. I could be wrong, but my understanding of the technology is that the old electro-mechanical switches, which AT&T used long after the invention of the digital switch and its use by competitors and other international systems, did not record this information by default. Thus wiretaps needed to basically put a type of recording device on the loop in order to detect calling activity -- but they could do it (because of the dialing "sparks" or the digital beeps indicating the connection). This was called a pen register (outgoing) or trap and trace (incoming). After the introduction of digital, there was a debate over whether the switches should be designed by law to record this information, or whether they should allow "plug-in" wiretaps for the convenience of law enforcement. Per CALEA (1994), this became US federal law.

The short answer is that with digital switches, the phone company (contrary to some opinion above) had little interest in recording this information; law enforcement, however, had lots of interest. But digital switches would have been more difficult to wiretap (for a variety of technical reasons), so legally they are required to have the capability built into them.

Thus, for story purposes, you could have a need for a wiretap and thus posit an exchange that is either electromechanical or digitally converted for wiretap interface -- or if you have a need for NO wiretap possibility, an exchange that was digital AND without such an interface.
posted by dhartung at 10:15 AM on April 13, 2012