Sitting here quietly and my iPhone beeped and a text message came in - "841138 is your Amazon security code" --BUT I have not been on the Amazon site for any purpose today or over the past several days.  I immediately went there and changed my password then called Amazon customer service.  As the lady explained, someone may have obtained my email and password in some fashion [how I don't know and I had an excellent password, I thought] and tried to buy something or get into the account for some purpose.  Thus, since I had 2-factor authentication set up, they couldn't enter because the text came to me with the code, not to them.  I know I harp constantly about passwords, password managers and security, but this is additional proof of the need to prevent easy access to one's accounts.