The newsletter is intended for people using its HIV and other sexual health services, and gives details of treatments and support.
This strongly implies there's some medical issue with all the recipients of this e-mail newsletter. After all, why would someone be subscribed to this who is not HIV positive or has some other affliction? And if you read the article, their full names were included in the list, as is common with e-mail. Frequent gaffe or not, this is a huge breach of privacy for those involved.
I'm curious... does anyone know if there a way to create a mailing list in Outlook (or whatever they used) such that it can ONLY be sent via BCC (at least without taking obvious steps)? If not, why in the world is that not a feature? If you're requiring an employee to manually choose the correct field (which typically isn't the default field) every time the mailer is sent out, then it's only a matter of time before they get it wrong, and the whole damned list gets sent to everyone. We see this blunder being made all the time. You'd think someone would have found a solution other than telling the operator "don't be an idiot", because *everyone* makes mistakes from time to time.