UFO defence tactic?

Ever since we have been driving cars and using electronic devices and whatnot, UFO's have been turning them off.

Classic story: Joe Blogs is driving down the deserted back road, comes to a railway crossing, and there are lights. He slows down, and the lights get closer and closer, until he realizes that's not a car/train! It's floating!!!
And then his car turns off, radio and lights don't work, and the camera changes scenes.

Now there have been heaps of reports of UFO's shutting off cars and stuff in the real world.

What if this shutting down of electronics is a defence mechanism?

Think about it! All they have to do is shut down the threat, whatever that may be, and they're free to do whatever they want!
This would also help in abducting people and all that. What wouldn't it help with?

I don't know if there is another thread on this somewhere. I searched, but didn't find anything. btw I don't really think that aliens have made it to our planet yet, but each to their own.