The people complaining that the media is "lying" by calling Sarah Hussein Obama Barack's "grandmother" are actually the ones who are saying that their view and terminology for family is the only valid view and the media should identify his family by their standards. You are directing your complaints to the wrong person.
If Obama identifies her as his grandmother, she's his grandmother. If a man identifies his adoptive mother's step father as his grandfather, that's his grandfather. Family bonds don't need special qualifiers and aren't trivial just because they don't come from blood. A family in which no children are related to each other or their parents is still a family full of brothers and sisters with a mother and a father. And no one should be chastized for excluding "steps" and "adoptives".