On Wednesday, the president was talking with youngsters at the White House Youth Summit on the Affordable Care Act. During his talk, the president noted that he is not allowed to own an Apple iPhone "for security reasons". The president does have an Apple iPad 2 which was given to him by none other than the late Steve Jobs during a Silicon Valley dinner back in 2011. Obama says that only 10 people have his personal email address. The two presidents prior to Obama, George Bush and Bill Clinton, did not use personal email.
While the iPhone does have clearance for Department of Defense employees and some government agencies, this clearance is well below what a presidential phone needs. A BlackBerry model from 2007 is the only handset owned by the president that has been certified to be used by him.