What if aliens are for real?

I am a fan of science fiction that sometimes I imagine a space craft landing on the roof of a building. That the passengers would be kind as to be diplomatic in its approach. And then the security guards of the building would appear and shoot the visitors. That is a nasty idea but it is realistic. Maybe the main reason why aliens do now show themselves is because of man’s penchant for killing strangers.

I wonder if the aliens come and what would really happen. In this time of the pandemic that protests and riots are happening all over the world we probably need the aliens to change the scenery to a better one.