Anecdotal: I participated in the reddit secret santa back in ... 2012?! and we all "won" a certificate from guinness records. Except ... that you still had to buy it as a physical copy. And so some poor marketing person from guinness sent this email to all the participants - no bcc, not even cc. And then the frist person replied. Another. And another. It was a party.

So guinness issued an apology (and hopefully didn't fire the person). And we got the certificates - as far as i remember - just for shipping and handling. Yay.

Years later, people on the list still write to "all" - its a weird group, with secret giving in common but nothing else. I wonder if anyone from this list is lurking here ...