Alien Base: The Evidence for Extraterrestrial Colonization of Earth: NON-INTERFERENCE
Why then were aliens coming here? ‘The answer is that this traffic is only a thin trickle in the vast highways of the universe,’ explained Janus. ‘The Earth after all is a galactic backwater inhabited by only half-civilized men, dangerous even to their neighbours . . .
Most of these vehicles are robot-controlled space probes monitoring what is going on. Some are manned in order to oversee the whole programme and to ensure the probes do not land or crash by accident.
They must also ensure that evidence of their existence is kept away from the vast majority of Earth’s population. You must be well aware of the damage which your own explorers have done by appearing and living among simple tribes, often leading to a complete disintegration of their society and culture . . . Such impact is far too indigestible and only the most developed societies can cope with such contact . . . The basic principle of responsible space exploration is that you do not interfere with the natural development and order of life in the universe any more than you should upset or destroy an ant heap or bee-hive . . . You will have to grow a lot older and learn how to behave on your own planet, if indeed you do not blow yourselves up between times, before you are ready for galactic travel.