Sudden flash of lighting: both Walt and Micheal, plus Locke, came back to the "Real World" from The Island at a certain point: Walt and Michael before the rescue of the Oceanic 6, Locke after this.
How is possible that no-one recognized them, even if they were in disguise? I mean: is a fake name enough to prevent everyone to recognize a person? Is really possible that no-one, among people that knew them before, will aknowledge them after?
While Walt was living in his granma house everybody knew he was dead, and so for Jeremy "Locke" Bentham...
I really hope you're going to get what I mean because this thought is making me crazy!