Records of calls made using *67

May 16, 2007 6:29 PM

When a caller uses per-call blocking (usually activated by pressing *67 before dialing the number) to mask their identity to the receiver of the call, would subpoenaed phone records for the caller's outbound calls still show the number they dialed?

And second, does anyone know how far back the records of call activity are stored by phone providers?

I represent a client in a case where a major question is whether an opposing party has called my client during a specific time period. If I can prove that the opposing party HAS called my client during the time period in question, this will largely destroy the opposing party's credibility, because I expect her to deny under oath that she has called my client. The only problem is that she has always called from a masked number, so that "PRIVATE NUMBER" always shows up on caller ID.

(I realize the answers may vary from provider to provider, so informed estimates are welcome).

posted by jayder to technology (9 comments total)

"Yes" and "pretty much forever", respectively. Caller ID has nothing to do whatsoever with the time and billing records used by the telco, it's just a little "memo" field that's sent to the call recipient.
posted by majick at 6:45 PM on May 16, 2007

Be aware *67 is not effective for 911, 8xx and 9xx numbers. The phone company still logs your phone call, and to normal recipients will block the CID information, but to 911, 8xx or 9xx numbers the CID information is still passed on, dispite you dialing *67.

As for it showing up on a call record - yes. It will show up on the caller's phone records.

As for history? It varies by carrier, but I am sure there are some statutes that say it needs to be retained for x years.
posted by SirStan at 6:46 PM on May 16, 2007

what majick said: ANI
posted by dorian at 6:55 PM on May 16, 2007

Follow-up from a MeFi user who prefers to remain anonymous:

My experience is that it is possible for someone, with a little effort, to block their number from even phone company records.

I involved the police when someone was calling me at home and blocking caller ID so "private number" was all that showed up. After weeks of the detective subpoena-ing the phone records and assuring me that the number would be easily traced despite the blocking and the caller arrested, I was eventually told that the phone company had "dumped the tower" where the calls were coming from but still could not track the number. Apparently, the caller had been using some sort of paid switching service that makes it much harder to track. The implication was that if all he'd done was use *67 they'd have been able to trace the number, but this extra step made it impossible.

That's all I was told, I don't understand it completely but maybe someone else can fill in the gaps. But it seems likely the only way you'll know for sure if your caller is trackable beyond the *67 is to subpoena your client's phone records and see what turns up.
posted by jessamyn at 7:08 PM on May 16, 2007 [1 favorite]

it's safe to assume that you're never private but closing the phone line account in question, this I am being told, makes it a hell of a lot harder for phone companies to come up with your information when asked. consider it only a delay though.
posted by krautland at 9:25 PM on May 16, 2007

Your phone company probably offers a "call trace" service. Around here it works like this: You can request a trace by (getting a dial tone and then) dialling *57 immediately after the call. The phone company will only give the resulting information to the police. If the police request the results of the trace, there's no charge. If the police do not request the results of the trace there's a $10 charge (and you don't get the information). Check with your phone company about how it works in your area (there's probably a description of such services in the front of the white pages).

As far as Call ID goes, blocking Call ID alone has no effect on the phone company's ability to track the call. The telco's records of the call have nothing to do with the Call ID info.

In addition, as I understand it, the packet of call ID information with the name and number is still sent even when *67 is used, but there's a 'switch' bit in the packet to indicate that it should not be displayed (e.g. if it's a 1 then display the info and if it's a 0 then display 'Private Caller' but the info is still sent). If your client happens to be receiving the calls at work at a company that has its own VOIP telephone network for which the company develops their own software, they might even be able to cause the Call ID info to be displayed even when the caller uses *67.
posted by winston at 9:52 PM on May 16, 2007

CID and ANI are trivial to spoof. The information about how to do so has been widely distributed on the front pages of national newspapers. If you were my lawyer, I wouldn't pay $0.10 for your strategy on this.
posted by paulsc at 11:21 PM on May 16, 2007 [1 favorite]

I understood the plan was to subpoena the caller's phone records, which has nothing to do with tracing, ANI, caller ID or any of that.

I think it will work just fine unless they made the calls from someone else's phone.
posted by Bokononist at 12:37 AM on May 17, 2007

I wouldn't pay some people here $0.01 for reading the question that was actually written. It appears that majick and Bokononist are the only people who have answered that question so far, which isn't about ANI or Caller ID. Anyway.

My chief concern would be that the phone company might (and should, IMHO) inform the opposing party once you subpoena her records. So get her to make the false statement under oath before you issue the subpoenas. You probably already knew this, but just in case, I'm saying it here.
posted by grouse at 2:07 AM on May 17, 2007