I have to wonder if this is in response to the fraudulent denial of US beef imports by the Korean government:

The U.S. has called Seoul’s attention to the increasing number of Korean children deported for attending U.S. public schools on visitors’ visas. A government official said the U.S. Embassy in Seoul in a consular meeting with Korea on Friday made it clear that it will clamp down. “A senior U.S. official expressed his concern about the disadvantages such illegal acts by Korean parents can bring to their children in the future,” he added. Another government official said dozens of such cases are reported in some U.S. cities.

Most U.S. public schools do not check foreign students’ visa when they enroll. But the Department of Homeland Security is serious about tracking down students who enter the country on a visitor’s visa and stay after it expires. The embassy said if children are found out, they will not only be deported but risk being blacklisted.