Alien attack improbable or impossible

Pretty sure you've all seen a movie with aliens in it. There are very many of this so if you have not you should get yourself one. Despite being numerous all this movies unless it's ET depict one thing aliens attack us. This movies have been watched so many times that people are starting to believe aliens might attack us. From all this movies we also learn another thing, aliens are very smart even smarter than us humans. Being intelligent I would not attack a ladybug since according to me, it poses no threat but a lion I would attack. 

So aliens being as smart as they are would never attack us. This is because of our friend light(pretty sure even the army couldn't take a couple of aliens with plasma weapons and laser guns). 

The reason that for our sight is because light bounces off materials into our eyes enabling us to see. This means since light from the sun takes eight seconds to travel from the sun to earth, it means that the light we are seeing is one that left the sun eight seconds ago meaning that when we star gaze (a thing that I love doing by the way)we gaze into the past. Aliens being very many light years away, probably think we are in the stone age meaning we pose no threat to them. So being the sensible creatures they are, they would not attack us at least not in a trillion years or so. By then the sun would have already gone supanova(thank you physics).So the next time you read a physics book on light give  some respect. About those aliens to begin with I don't believe they exist and thanks to light they wouldn't attack so I'd go for IMPOSSIBLE.