Because somebody on this site likes to act like a 13 year old.
Seriously, did MD steal your candy or something? I'd never expect this kind of immaturity in a place like this. It's not even as if they blocked the name of a site that was rash or crude or something. They blocked MD, one of the better technical sources of information for Mustangs out there.
Oh and they sell stuff. Maybe thats another reason somebody got their panties in a bunch. Get a grip.