Anonymous Authority

The fallacy of appeal to anonymous authority occurs if an unspecified source is used as evidence of the claim, and it is impossible to verify the source & the argument’s credibility.

Many flat-Earthers claim to know someone who knows someone who knows a pilot, surveyor, scientist, professor, etc., who has proven Earth is flat. But it is impossible to verify these supposed “experts” & their views directly. Inventing an “expert” to support their position is the fallacy of anonymous authority.