I see four possibilities.
1. It is untrue.
2. It is true and
a. The visitors are malicious.
b. The visitors are benign.
c. It is staged by humans.
If it is untrue there will be a lot of 'channels' with egg on their face. (A long time ago, prophets who were wrong would be stoned to death - I guess the people didn't like being deceived back then)
If it is true, I am not sure how we will determine the visitor's intent or whether it is staged.