Oof. Small business I'm a subscriber to just sent an email to 312 customers (which might be all of them) *via cc* 🤦♂️
Worst part: the email was apologizing for a (much smaller) mistake. Double oof.
Sent them an email informing them as gently as I could that they just blasted their mailing list out to everyone and saying they should probably notify folks and check with their lawyer just in case.
So, to anyone out there emailing lots of people: use bcc of course, but also this is one of the many reasons you should use some sort of mailing service for anything more than emailing amongst friends.