The situation is not symmetrical. For the recipient of the call, it is a privacy issue.

If you are the one initiating the connection, your expectation of "privacy" (or more accurately, anonymity) is lower. I have no obligation to allow that connection if you refuse to offer any identifying information.

I see this as analagous to deciding whether or not to open your door to a caller. If the person is masked -- their identity obscured, would you open the door? Now consider that person being unmasked, but unknown to you. Then consider that person being known to you. You have the option in all these cases to remain hidden in your home -- to not reveal your presence or identity to the caller.

If someone wishes to make telephone calls without their number being visible to the recipient, one can consider this analagous to a masked caller at your front door. I believe the phone companies in the US offer the ability to block calls that have caller ID blocked, presenting the caller with a message that they must not block caller ID in order to get their call to ring through.

yours,
Michael