What is the name for the phenomenon in which a person tends to strongly believe information that is relatively accessible but requires some effort to find or execute, as opposed to summarized facts handed to the public by an official figure?

For example, most people will believe in a whatsapp chain (accessible information) that says drinking arbitrary amounts of water makes you lose weigh (easy but quirky solution) stronger than the recommendation of a medic (official figure) to eat smaller rations of food (summarized fact).

You could do the same for anything else. Colds and temperature, "toxins", drug abuse, habits. Could be finding information on your own or hearing it from an emotionally-trusted source rather than an official figure is what cause it, What would be the name for this?