Although it's no secret that members of Microsoft's leadership frown upon employees who choose an Apple iPhone over one running the company's own Windows Mobile operating system, approximately 1 in 10 still veer towards the forbidden fruit and sometimes go to great lengths to conceal them on the job.

In a lengthy profile on the perils of being an iPhone user at Microsoft, The Wall Street Journal cites two people familiar with the matter in saying that nearly 10,000 iPhone users were regularly accessing the Microsoft employee email system last year, representing roughly 10% of the company's global headcount.

The trend at Microsoft has flourished in the face of chief executive Steve Ballmer, who has a long track record of making inflammatory remarks about the Apple handset and expressing his displeasure with staffers who use one. Perhaps the most infamous example of this came last September during a private company meeting when he caught an employee using an iPhone to snap a photo of his entrance.

Ballmer grabbed the iPhone from the employee, made some remarks as the crowd booed, then placed it on the ground and pretended to stomp on it before walking away. During his ensuing presentation, the Microsoft chief again turned his attention to the employee with a few more teasing remarks.

In yet another sign that Microsoft was determined to curb iPhone adoption amongst its own kind, the Journal notes that the company "in early 2009 modified its corporate cellphone policy to only reimburse service fees for employees using phones that run on Windows Phone software." The Redmond, Wash.-based software giant would later claim the move was "part of a broader cost-cutting plan."

Still, many employees are unwilling to sacrifice their iPhone and regularly adopt measures to hide their handsets when in the presence of the company's top brass, according to the Journal. "While rank-and-file workers tend to use the iPhone openly around peers, some conceal them within sight of more senior executives.," the paper reports. "One Microsoft worker said he knows several colleagues who try to disguise their iPhones with cases that make them look more like generic handsets."



Ballmer laughs off the iPhone in 2007.