https://www.washingtonpost.com/world...18d_story.html
http://www.jpost.com/International/I...er-swap-441702
http://www.bbc.co.uk/news/world-middle-east-35333656
apparently it's a prisoner swap. 4 dual Iranian-Americans are being released in return of 6 or so Iranians imprisoned by the US. on the day that sanctions are going to be officially lifted, John Kerry is currently in Vienna and it is expected that the sanctions are going to be officially lifted.