If you recognize the title of this post, you are probably following the dust up promoted by Glenn Beck over Abdul Rahman Ali Alharbi (e.g., here and for another perspective here).
In short, Beck believes the Obama administration is covering up Alharbi’s culpability for recruiting the Boston bombers. Independent sources including Fox News have investigated the situation and found nothing any different than what the government is reporting – Alharbi was at first thought to be involved in the bombing but was actually in the wrong place at the wrong time and was wounded by the bombing.
I don’t know enough about the way Homeland Security handles security threats to comment fully on this matter, but I have been following it as an illustration of belief perseverance.  Once a person gets an idea fixed in mind, even the disconfirmation of the original evidence cannot shake it. New reasons are sought and secured to make the original proposition (there’s a cover-up, I tell ya!) seem plausible.
I might add to this post as new information comes up. I think this interview from The Blaze yesterday is intriguing because it actually seems to undermine Beck’s chronology of events.