Today I received an email from email@example.com that contained (inter alia) the following text.
You are receiving this email because you are listed as the developer of an extension for Firefox. If you do not want to receive these updates, please log into addons.mozilla.org and delete your extension(s).
I was unaware that I had created any extension. Upon logging into the addons site, I find that I have no add-ons registered. (I see this.) So I should not be receiving emails of the sort that I did receive, and there is no easy way for me to stop receiving them. This is bad.