BAMF: The point keeps getting missed by these "scientists" and "experts". The segments of wall are intended to funnel/divert illegal crossers to specific areas where the border patrol can focus their efforts. Say the 2,000 mile border has ten 20 mile long gaps. Each gap conveniently has a detention facility and a border patrol field office nearby. Agents at each of those stations can focus 95% of their patrolling to those gaps, and only venture along the barrier when the seismic sensors pick up tunneling activity. The sensors by the way that the democrats like to pretend are the best things ever, are no good by themselves. The best they can do is tell an agent who might be 100 miles away that something large enough to maybe be a person walked by at such-and-such a time, now go find him. If the sensors are accompanied by a wall on the other hand, it will warn agents that a tunnel is being dug which gives agents more time to prepare to respond because digging a tunnel takes time.