What makes me chuckle about this subject are the religious people who will always warn of the 'dangers' of mediums, spiritualism, fortune telling etc., when it is just a different form of exactly the same thing.
I'm not religious, or a fan of religion. But generally priests, vicars, imams, rabbis etc. sincerely believe in what they do, do not charge by the hour, and are regulated to some extent by the religion they practice.
On the other hand, there's a good chance that a medium will be a charlaton on the look out for a mug.
So whilst there might not be the horrible spiritual dangers the religious types refer to, there are definitely other real risks.