Microsoft Teams doesn't help
Experian sent me an invitation to an in-person "Data Governance Breakfast Briefing" in November 2024. There were 27 other email addresses exposed (some interesting attendees in fact). Experian didn't respond to my concerns, didn't apologise and I didn't attend. Two attendees did however contact me - both wondering why I didn't attend - and both in the Data Protection profession.
When I investigated further, I discovered the invitation was generated in Microsoft Teams via Outlook, which didn't allow attendees to be placed in a BCC context or hidden from each other. That apparantly was only possible from the web based Teams portal.
Just checking and this still seems to be an issue today - unless you then switch the "Teams meeting" option off after creating the event, which reveals an option to "Hide attendee list", and then you send. What a Microsoft mess.