The Magnitsky Act is a piece of U.S. legislation at the moment, which has three basic features: it publicly names the names of the people who are involved in human rights abuses; it bans them from entering, in the U.S. case, America; and it freezes the assets and disallows any financial institution or U.S. business to do business with the people who are on that list.
The Magnitsky Act applies in America to the people who were involved in the Magnitsky case, and it applies to people involved in other gross human rights abuses as recognized by the U.S. government.