reply to Doctor Olds
Re: [Scam] Card Services relentless phone calls revisited It's a common misconception that only/just because it's an 800 number that they can get your number from blocked caller id.
Actually, it's really any company that answers and processes calls digitally - it doesn't matter if the number is toll free, or regular toll. As long as they're using a computer system to receive calls, they get the CPN data directly. Since calls are not terminating on analog caller id displays at a landline provider, they're not obligated to honor the privacy bit.
Some people will think of magical things with ani/CPN/BTN etc. but the fact of the matter is the vast majority of these phone numbers are simply ignoring the privacy bit. All the CPN is just a call-back or "directory" number that is used to populate the caller id display of the callee's Pots or Pots-like replacement service. Once you call into a computer system, then your number is fair game. There is no obligation to honor the privacy bit at that point.
What we're probably referring to for toll free numbers is the BTN or billing number. I guess that's the ANI as some might call it. Still, that information is not passed to the callee on the fly. It's only used for billing purposes witin the PSTN, so it's really not an "unblockable caller id". However, they'll be able to view the billing number on their bills once the call is billed.