If those innocent shareholders insist on following social media gurus without bothering to learn the rules that govern penny stocks, and without doing any research of their own, they need to realize they're running a risk.
The "real culprit" here seems to be OTCMarkets who moved the companies to Pink without compliance with 15c2-11.
I suggest that anyone who purchased shares based on that action file a formal complaint with both the SEC and FINRA, which may spur those actual regulators to investigate OTCMarkets and how this occurred.