A simple technology could secure the border for a fraction of the cost of a wall — but no one's talking about it - Business Insider

Amid the ongoing debate over whether to fund President Donald Trump's border wall to the tune of $5.7 billion, experts and industry leaders say there's a far more effective technology - at a fraction of the price. ....
https://www.businessinsider.com/fiber-optic-sensing-technology-vs-border-wall-2019-2