Can't spoof that.
Yes, but how many of those 32 million email accounts were paying customers? I don't know about Ashley Madison but a lot of dating sites will let you sign up for free, "SIGN UP FOR FREE!" is in the banner ad they use, but you have to shell out credit card info to actually use the site past the introductory page.
It goes without saying, if they have your credit card on file, you're screwed. It's best at this point to go seek out marriage counseling or a good divorce lawyer (and probably have a private conversation with your boss).
This being said, there's a potential here for a huge number of people who never had much to do, if anything at all, with Ashley Madison to see their lives upended.
Does anyone really think Tony Blair set up an account with AM? And if not Tony Blair, what about the countless John_Smith@yahoo.com or the other John_Smith@fbi.gov (with a security clearance)?
Have you ever received a spam email from your own yahoo.com address? I have.