WPMU AD on my SITE???

One of my members contacted me today and asked: What is this WPMU, and why are there ads for it on my blog?

I looked into it - and yes - indeed, there is an AD for WPMU ON MY SITE IN A SPOT THAT IS COMPLETELY AND ABSOLUTELY INTRUSIVE. Directly above the TITLE block when someone creates a new post.

I'm sorry but this is WAY OVER THE LINE! I am not an affiliate, I did not sigh up to be an affiliate, and I am absolutely NOT OK WITH THIS BLATANT Imposition on my network.

How do I remove it? Or should I just remove all WPMUdev products from my network and be done with it?