Russia's Foreign Ministry announced Saturday that it confirmed a list of American citizens it will bar from entering Russia, in a retaliatory move against the United States’ adoption of the so-called Magnitsky list, which imposes sanctions on Russian officials who have been linked to the 2009 death of the whistleblower Sergei L. Magnitsky.
http://www.nytimes.com/2011/10/23/world/europe/russia-will-bar-some-us-citizens-in-retaliatory-move.html?_r=1