In the video below, Richard Dawkins interviews Derren Brown as part of his "Enemies of Reason" series.
One of the key questions he is trying to get at is (to paraphrase): if a lot of stuff such as Fortune Tellers, Mystics and Astrology is simply not true, at what point should the leaders/"spreaders of falsity" take accountability for simply lying? Put differently, how many of them know that what they are doing/saying is false or misleading, but do it anyway?
A lot of people use the, 'it does no harm' logic to accept crazy beliefs. In some cases, the false beliefs may actually do good. Does it matter if something is wrong but leads to a good conclusion? The age old question of is lying about the Jews in your basement to the Nazis wrong? Clearly it is not. So, is a person all dressed up as a fortune teller who is just cold reading doing good or harm if someone believes it to be true? What if it gives them comfort and does no harm?
I think the case for dispelling falsity where it is doing harm is very compelling. This would be Dawkin's logic for essentially being an 'evangelical athiest'. Post 9/11, he has been on a crusade of sorts to de-stigmatise Athiesm with the belief that many of the world's problems are caused by fanatical beliefs that have no founding.
The counter argument is that religion (even if false) can give hope, comfort, and a sense of community.
I guess there is no clear answer and all this is rather murky.