This might be the world's first high-profile live-tweets of an entry-visa denial.
New York Times columnist Nick Kristof (@NickKristof), who knows how to use social media in smarter ways than most journalists (see my April 2012 post about his fans using social media to mark his birthday), found himself denied an entry visa into Bahrain earlier today. He took to Twitter to complain and bring attention to the situation there.
Kristof has written a lot about human rights abuses by Bahrain, an ally of the U.S., so that's why he was denied a visa at the airport. This happened despite the fact that U.S. citizens can transit through the kingdom without a visa.