According to a source with AllThingsD, the lawyers at Microsoft Corporation (NASDAQ:MSFT) and Facebook are duking it out over the hiring of Carolyn Everson. Everson was the global ad sales head and was hired as the VP of global sales at Facebook. Microsoft is considering blocking Everson from using any strategic information she learned while at Microsoft or from contact certain ad client companies on behalf of Facebook.

Facebook VP of Global Sales Mike Murphy is leaving the company for personal time. “For the last five years of hyper-growth here, I have been focused on Facebook,” stated Murphy. “Now, I felt it was time to shift that focus to my family.” Murphy is ex-Yahoo! executive that went to Facebook in 2006. [AllThingsD]