Athar, Sohaib (ReallyVirtual). “Helicopter hovering above Abbottabad at 1AM (is a rare event).” 1 May 2011, 3:58 p.m. Tweet.
I read about this in the American Historical Associations blog which gave me the link to the Modern Language Association's site. Read the AHA post to see that many questions have arisen about the correctness of this citation. Good questions are being asked and references are given to other articles. The main questions relate to the provenance of the actual news in this example.