1.   Often, it just forces migrants into the arms of professional traffickers.

2.   One reaction is to put up stronger barriers and force migrants to more dangerous measures.

3.   But to pay back their passage, some migrants are forced into prostitution.

4.   It argues that heightened U.S. patrols have forced migrants into more dangerous terrain.

5.   It wants to force migrants into isolated mountains and deserts where the terrain is rougher, the weather more brutal and the crossing time longer.