Why this particular political fluke is being drawn into the public eyes is anyone's guess. A selfie between the President and a person is a political choice and should not be twisted into a national security or legal issue. The selfie is no more threatening than a paparazzi peeping tom. Although it may be annoying or have bad side affects afterwards to the person, but that is how the political machine tumbles. Restrictions to the public access through legal means is a overthrowing everyone else's personal rights. If the President doesn't want to take selfie, then don't.
I think that president Obama's selfie should be considered harmless. He did it as one of many examples of his easy-going personality and he shouldn't be concerned about potentially harmful usages of this selfie, not because they are in fact, real, but because he didn't mean any harm and that's good enough.
The picture of Obama that is causing the selfie issue is not a serious enough one for Obama to feel threatened. He wasn't photographed doing anything illegal, or anything that can damage his reputation - his image was simply used in a commercial. Aside from suggesting he has a bias towards phone provider, it doesn't affect him professionally at all.
Why should the president feel threatened by just a photograph. I don't think its a big deal so there is no need for Obama to feel threatened at all. So many pictures of him afloat everywhere these days so even if this one spreads around it should not make any difference.