Cj
The PSA 727 actually hit the cessna, not the other way around. Simple physics. the faster plane runs down the slower plane. Approach speed of most jets is faster than most light aircraft can achieve.
So its not something that can be done casually.
Furthermore airspace is a lot more carefully controlled these days. An aircraft in an arrival corridor not talking to anyone would cause all kinds of problems.
basically you could get the same effect by just launching a bunch of balloons. Think of the barrage balloons of WWII because the jet is gonna run into the smaller plane, not the other way around.
Wino