What’s up with that Twitter hashtag on your Fox TV show?

During last Friday’s episode of the Fox sci-fi show Fringe titled “Lysergic Acid Diethylamide,” Walter, Peter, Broyles, and Bellivia were tripping on LSD.  I almost thought  that I was tripping when I saw “#Fringe” just above the logo of Fox 5 (WTTG – the DC affiliate) in the lower right hand side of the screen (different affiliate logo pictured below)....