Specifically, Salesforce's chief legal officer Burke Norton argued that if Microsoft owns LinkedIn's dataset of "450 million professionals in more than 200 million countries," they could deny competitors from using it. But even the combination of software and social information could give an unfair advantage, sources told The New York Times. Of course, the company is hardly unbiased: Salesforce had a competing bid for LinkedIn.

Microsoft fired back, noting that the deal has already been cleared in the United States, Canada and Brazil, and that the advantage would not outpace Salesforce's existing dominance in the customer relationship management (CRM) market. Whether the EU competition authority ends up blocking it or not, the call for scrutiny could lead to a deeper investigation into the deal, potentially dragging it out for months longer.