GOP presidential candidate and Kentucky Sen. Rand Paul says that while he is all for helping those in need, the United States should be "very, very careful" in weeding out any potential terrorists."I read in the newspaper one young man that had just left Afghanistan in the last few weeks, he was 19 years old, and all we had for identification was political asylum from Hungary. No preceding documents, no passport," Paul said Thursday on Fox News Channel's "Hannity." "This is a terrible humanitarian crisis. It's also a recipe for disaster if tens of thousands of people want to attack us," Paul said.President Barack Obama has ordered the United States to take in at least 10,000 refugees "Even of the 60,000 Iraqis that came over after the war, some of them, even in my little town, Bowling Green, Kentucky, have tried to attack us," he said.