*** PLEASE WITHHOLD MY NAME -- PUT A *67 ON IT PLEASE ***

Obviously, one should not think of using *67 (11-67) when calling
toll-free numbers (800, 888, 877, 866), as the ANI is deliverable.

But even when calling "POTS" numbers, don't always expect *67 to be
"secure". Your ANI is STILL deliverable. The only "privacy" that you
are "guaranteed" of is that *67 will "flag" your originating number as
"not to be delivered as Caller-ID over the called party's local
loop". The destination central office will most likely still have your
telephone number in its records.

If the called party considers such calls as harrassing, they can
always use various "annoyance call" complaint procedures through their
local telco, which could include THEIR use of *57 (11-57) Call Trace,
or other more traditional "trap-and-trace" methods. They may also have
"anonymous call rejection" as well, so that so-called "private number"
calls won't even get through.

And then there are the LD-carriers and CLECs/etc. which might not even
honor the "privacy flagging" of your calling number when you as the
calling party use *67 to call the desired number. Sometimes these
CLECs and LD-carriers simply have things mis-configured, and if
properly alerted to the fact will most likely correct the situation,
but there are other CLECs/etc who probably don't even give a sh**.

Also, don't expect to "hide behind a PBX" will necessarily prevent or
hinder your calling number from being tracked. The calling number might
not necessarily go "out" of the PBX on the network, but your PBX staff
might keep records as well ...

There are numerous ways to prevent SS7 Caller-ID from being delivered,
such as the "cheapo-LD" companies, loop arounds, etc. that you suggest
 ... but even with all of them, I still wouldn't want to be calling
from a number that is associated with me because there are still ways
of tracking numbers near the calling end of the call, usually via ANI,
which the calling party usually has NO control over delivery or
recording of.

Mostly -- I would NEVER attempt to believe that *67 protects my
privacy.  It might "appear" to do so on an occasional call where I
don't want the called party to "immediately" know my number. But in
most cases, where SS7 connectivity is there, my number has been
delivered throughout the network all the way to the called party's
telco central office. And who knows how my number could be
recorded/etc. by them for future proceedings.

(again, Pat, please keep my name with-held from this post ... thanks)

[TELECOM Digest Editor's Note: Very good advice. *67 really only works
well in cases where it is administratively inconvenient to try and
search out the caller, and it doesn't really matter anyway. I am 
reminded once again of how several years ago obscene phone calls to
Queen Elizabeth were made by someone who thought they could 'hide 
behind a switchboard and not get caught'. Go back now to the early
1960's ... the Queen's personal staff had been getting at least one,
sometimes two or three calls daily from an 'anonymous' admirer which
were (to put it kindly) obscene, and to be more to the point very
scurrilous and sick in nature. I am quoting now from the Chicago
Tribune's account. For the first few days of the calls, the Queen's
personal staff simply laughed them off, and had a great joke of it. 

But eventually, they began to get tired of the game, and put in a
complaint with British Telecom asking for assistance in stopping the
calls. When someone asks, or makes demand under the Queen's name, the
underlings usually hop to it, and they did in this case, beginning
to 'trace' the calls. BT eventually got back with a report that the
calls were originating in the United States, and they asked their
associates at AT&T in White Plains, NY to look into it for them. AT&T
did investigate it, and eventually traced the calls back to Illinois
Bell which in turn found that the calls originated in the 'Chicago-
Superior' central office. A technician (or whatever they called them
in those days) in turn found the calls were originating from the
switchboard at WHItehall 4-6211 -- the Lawson YMCA. They got that
far in their tracing efforts after 4-6 weeks; faster and more diligent
in their search than any other instances, because it *was* the Queen
after all. After all, being an international call, they probably would
not have looked that far had it been any 'regular' person. 

British Telecom formally asked for help on the matter, and a day or
two later, *Chicago Police* showed up and served a search warrant on
the chief operator at Lawson asking to look at her toll tickets, which
were just old paper things in those days. After a couple hours of
reading through reams of paper 'tickets' they found what they
wanted. But they had to build a complete case out of it. Later that
day, a technician from Illinois Bell came out to Lawson with some
equipment. He took off the back of the switchboard, walked inside it
and starting attaching his equipment (which were simply some wires to
a recording device.) Remember, in those old days, multi-position
switchboards were big, humongous things; Lawson has a couple thousand
rooms and another hundred or so administrative extensions off the
board. In those days there were a couple operators per workshift and
the supervising operator.

The man came out of the inside of the board, set up his recorder and
with a glare in his eyes said to the two operators on duty, "and you
two had better keep your traps shut. If you tip him off, the police
will arrest you also for interfering. Just keep plugging your calls."
It was not uncommon in those days of manual service for an operator
to be friendly with a subscriber and maybe tip him off to trouble 
brewing. The women did not intend to lose their jobs on account of
this sick phreak.  Sure enough, a bit later that day or the next, a
call was recorded on the tape machine. Police made an arrest and the
Chicago Tribune's account of the incident was entitled 'the Queen
chats with another sick queen.'  

So, star-67, you are quite correct. Depending on how bad they want
you, they will find you. *67 doesn't do any good, its just a small
consumer-grade stumbling block. I am not suggesting that spammers 
(or their innocent victims as the case may be) warrant *that much*
attention. Anyway, we don't harass people, do we?  We just make
inquiries about things we saw on the net.   PAT]