The U.S. Department of the Treasury's Office of Foreign Assets Control (OFAC) has published the names of individuals who are now on the Specially Designated Nationals and Blocked Persons List (SDN List). This action is based on OFAC's determination that certain legal criteria were met. As a result, all their property and interests in property that fall under U.S. jurisdiction are blocked, and U.S. persons are generally not allowed to engage in transactions with them. The list and more information about the sanctions are available on OFAC's website.
Simple Explanation
The U.S. government has put some people on a special list because they broke certain rules, and now they can't use their money or things in the U.S., and people in the U.S. can't do business with them.