In olden times, it was fairly easy to identify the sources of misinformation and cultural ignorance: They were either commercial entities that profited from misleading the public, such as tobacco companies, or conspiracy theorists and other inhabitants of the lunatic fringe.
“When it comes to misinformation, I normally tell people not to trust information unless it comes from a trusted source,” says Mark Dredze, an expert at Johns Hopkins University on how health-related misinformation and disinformation spread via social media. “Don’t take your health information from random websites and don’t take any medication without talking to your doctor.
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Source: Hiltzik: In coronavirus crisis, misinformation is contagious | Los Angeles Times