Of course they are. Trying anyhow. 2 suspected terrorists on FBI, DHS watch lists arrested at US border | American Military News
On Monday, U.S. Customs and Border Protection (CBP) announced that within the last two months, it caught two Yemeni nationals, listed on the FBI’s terrorism watch list, trying to cross through the same border sector.
So how many did they NOT catch? I guess we will found out soon.