The problem is that this forum, and social media in general, is viewed by a lot of people, certainly orders of more magnitude more people than actually comment. Comments such as yours misleadingly take advantage of human social traits, such as attributing more truth value to someone with authority, and avoiding people who have been negatively labeled because they must be outcasts. There are potentially thousands of people who's respect of Graham Hancock has been decreased to varying degree due to your statement. Using appeal to authority and ad hominem name calling are the most basic of logical fallacies and should be completely discarded.

This is completely unrelated to whether Graham Hancock is actually a fraud or not. The problem is with your comment, no matter who you are talking about. Anonymous authority on the internet is worthless, as is name calling. As a supposed academic, you should be providing sources and examples, the absence of which makes your statement about being an authority on the matter suspect.

I take issue with this because this sort of mechanism is currently used on social media to wreck great havoc on society, especially in the US where people's lives are destroyed and horrible politicians get into office due to supposed authorities calling people names on the internet. It's a far worse issue than you are acknowledging. The whole point of social media is to spread ideas. You are not an island.