The attacks of 9/11 changed a lot of things in the U.S. and immigration policy is no exception. In this clip from Homeland: Immigration in America, an immigration attorney explains that prior to 9/11, anybody could send a visa application through the mail and get approved with forged documents. Today, however, the process is much more closely supervised, with visa applicants required to appear for an in-person interview prior to receiving their visa and coming into to the United States.