My Amazon accounts appear to have been hacked, with the email addresses changed. (Which is how I found out - Amazon sent me an email "confirming" the email address change.)
I've sent messages to Amazon, but I don't know if they can get my accounts back to me.
If you see any suspicious activity from "me" on the Internet, let me know which websites. I have no idea if this is widespread. If you have any advice or help to offer, please let me know.
Check your Amazon log-in, and if you're fine, change your password anyway - just in case.
Wishing you all the best.