Have you tested making new e-mail addresses which have no connection to anything else, signing up for an ihub account with that new e-mail address, and seeing if you start receiving that spam at any point in the future?
I'm getting about 10 messages a day now, so is a friend of mine. The only site both of our e-mail addresses are connected to, that we can both think of, is ihub. And neither of us received any of this spam until after we both signed up, and he signed up very recently and only started receiving it after he signed up.