So skywall can get to **gasp** 300ft! and of course what happens to the net when it _doesn't_ catch the 'drone' on a windy day? So the airport puts out how many people to do this to cover 100 meters (that is slant range).
People thinking this is a good idea have never had to secure an airport. A modern airport boundary is from 8 to 20 miles long. So how many people with these 'skywalls' would you need? They would be hard put to protect a single house let alone an airport.