MIAMI, FL - MARCH 04: International travelers wait in line to speak with a CBP officer as they arrive at Miami International Airport on March 4, 2015 in Miami, Florida. Miami-Dade Aviation Department and U.S. Customs and Border Protection (CBP) unveiled a new mobile app for expedited passport and customs screening. The app for iOS and Android devices allows U.S. citizens and some Canadian citizens to enter and submit their passport and customs declaration information using their smartphone or tablet and to help avoid the long waits in the exit lanes. (Photo by Joe Raedle/Getty Images)