Walls aren't meant to be 100 percent effective nor the sole means of security. To say that walls don't work suggests wildly overblown expectations for the walls. Prisons have walls, and not because they don't work. They have them because they do, in fact, work. In the places along the southern border where the wall is in place, it's been successful in doing precisely as designed, greatly reducing the flow of illegal immigrants and drugs across the border.Be my guest..... Fact is every wall ever built in the history of man kind has failed at some point.