The Bcc or blind courteous copy is an insidious tool.
Let us examine.
I receive an email message in which I am given no reason to believe that I am not conversing with the author in private. In the same act of allowing me to believe I am in a private conversation, the “person” with whom I am conversing is secretly allowing (as a courtesy!) a third party to eavesdrop in on our “private” conversation.
Betraying a trust by sharing a private message as a courtesy? A courtesy is showing a gracious consideration toward others. Would sharing the stolen innocence of a minor with another molester be an act of courtesy? Imagine you are having a private conversation with your trusted loved one in the privacy of your bedroom, and your loved one has deceitfully allowed their secret lover to hide under the bed to listen in.
How evil is the person showing graciousness to one while simultaneously spilling the blood of trust of the other. Cunningly betraying the confidence of another while wearing the smile of courtesy. The Devil is indeed in these details.
Radical Flora Insurgents!