What is also interesting is that the group have used the term EXTRATERRESTRIAL which could be defined as any paranormal entity, so there is no directness whether the warning is aimed at aliens, space brothers or any other such entities - so what this message created by humans is really saying that we should be cautious what other lifeforms which are regarded as extraterrestrials may bring as gifts or offerings to humanity ( when such a time arises of course ).
Crop Circles are made by man RED COLLIE - Wake up !
Great piece of artwork Francesco - well done !