At the bottom of Robert Scoble's post on the problems of Twitter, he reveals this exchange he had with an Apple employee:

I asked someone at Apple why they made that deal [to integrate Twitter into iOS 5] and the answer was "because Mark Zuckerberg is a ****ing a**hole." Wow, insider politics between these companies is something to behold.

This highlights the continued animosity between the two companies. Our understanding from a source familiar with Apple's operations is Facebook makes Apple more nervous than any other company.

Why are these two enemies? At the D Conference in 2010, Steve Jobs said Apple couldn't work with Facebook on integration in iTunes Ping because Facebook's terms were too "onerous."

It sounds like Mark Zuckerberg wouldn't just kiss Apple's ring like everyone else which infuriated Jobs and company.

Anybody out there have more details on what's going on between these companies, email us at jyarow@businessinsider.com or call at 646.376.6037.