I once did some contract work for a company who were somewhat tardy in payments. When the manager sent an email to the contractors about his cash flow problems, he put us all in the To: header.
This resulted in one of the other contractors emailing the rest of us telling us that we’ll probably never get paid. This in turn led to more emails, and eventually we became an informal action group, each of us sharing tales of woe, as well as snippets of scandal.
The company folded, the manager went bankrupt, and was given a gaol sentence for crimes committed in trying to cover his financial problems.
We never did get paid, but it makes a good story — not using the BCC button can get you in deep trouble.