I don't see where you get that ProfWag... that's such a common knee jerk line when it comes to Mediums but I don't see how it would apply to the scenario's in question. Too, "taking advantage" of someone can arguably be a matter of perspective; if someone comes to me for a Reading and I know for a fact that I can give them tools or ways of processing information that will change their "negative" circumstances, how is this taking advantage? Not to mention the fact that they came to me in the first place...
Yes, when a Medium (in particular in that they do this more than psychics will) approach someone "with a message"... this is gross imposition and should be the first red light going off in a person's mind that something is askew. I've been called in to look at so many cases of this type and with but ONE exception, every single one of them were pure con-game. The "One" exception wasn't a case where money was being sought or any other form of compensation and so it was not investigated any further. All of the other cases (well over a dozen) ultimately involved a cash demand for several thousand dollars.
This whole thing is such a sticky-wicket in that the majority of folks, including those that are simply delusional, who do Psychic work aren't in it for the cash, fame, etc. they literally do it for the sake of helping others because they feel it to be a "calling" from "god". There is a minority however, that's set a standard of sorts in which it is a "business" or "vocation". Again, you will find that most in this category aren't out to be abusive to patrons but they are more inclined to manipulate them into a state of "codependency" for the sake of repeat business as well as referrals. It is from this group you will find the relatively small group of con-artists and predators. If you research most of these folks they do not rely on the Psychic or Spiritual theme when working their game, they can be very flexible. Too, those that do hold to this arena tend to not work alone, there is a network involved.
M. Lamar Keene (The Psychic Mafia) gave us a wonderful glimpse into this mode of operation but fell short... or I should say, wasn't able to foresee how this particular Hydra would transmute.
Today's "Psychic Mafia" is literally a "family operation" that typically focuses on small and mid-sized communities in which several members of the same family aid one another on a plethora of cons... scams that range from Contractor or Car Repair games to the Mediums & Psychics... even Evangelic Faith Healers so that the Christian side of things are better covered).
What makes this type of network so potent is that you have family members working legit jobs such as bar tender, taxi driver, concierge, hair dresser, gardening, etc. Their contribution to these cons being more akin to gathering intelligence on existing or potential marks.
Busting and exposing a group of this type is damn near impossible because it is literally "all in the family" and so, no outsider gets in (not even by marriage). Too, when it comes to the Psychics at least, so much fear is placed into the mind of the marks that they will not go against them... this, as I've noted, also ties to those cultural and religiously based influences. Too, the fact that these groups focus primarily on those people who feel they "can't" complain or do anything to "legally" deal with such criminals, such as illegal immigrants.
It's a very ugly and disgusting situation in my book.