The press has been reporting that the woman who carried out the San Bernardino massacre with her husband came to the U.S. last year on a K visa, raising questions about whether the K visa process can adequately vet people who may sympathize with terrorist groups. However, this is one of the harder visas to get.  To get the K visa the foreign national must go through a Consular process that includes an interview with the couple and background checks that are more stringent than probably for any other visa. While we can improve any process, it would be an error to abolish the K visa process as a whole for one error.