Radar / Radio. The reason they dont just 'land'?

I was thinking about this on the way to work this afternoon.

I had what some would class as a close encounter on Sunday just past. With something, possibly a military craft however it was indeed something.
While we were watching this out the window of my car, we had turned the radio right down to listen for engine noise or anything at all. While the second 'craft' flew over us and around us there was static / white noise coming from the radio of the car. Only in short bursts but non the less.


So, I remembered back to the Roswell incident reports I had read which 'claimed' that it was Radar that had messed up the UFO's systems and it then crashed, more so a pure fluke as apposed to any military defense system at the time. If this was indeed the case, does that not technically mean that now, we have got 'almost' a full protection system all ready in place to save from this happening again?

I mean there are almost daily reports now of things spotted in the skies at night, but never ever anything on the ground. Could the radio signals and phone signals etc being broadcasted from tower to tower be stopping the aircraft from coming below a certain altitude? If this was the case, then I cant account for the world but I mean you can get Radio almost everywhere here in a car so in theory (im no radio expert) then there would be waves going everywhere, and would these waves then not play with the flight controls some how?

Just a thought, felt I should post up.

I think if they can achieve interstellar travel they ought to be able to overcome some radio waves. And if these beasties are local, then they would never have gotten off the ground to begin with.

Would that not be an assumption? Because they have the ability to travel across space they would then have the ability to over come things which are simple to us?

I was only speculating on a report which came out a long time ago which gave the reason how that apparent first craft came down, and a possible reason why they are yet to land so far?

I dont think its as easy to say that tbh, its like when people say, "If they are real why have they not landed yet?" What 'if' this was a reason? More and more masts go up all the time to create better coverage, could this not be another plus to installing them? Less chance of contact.