https://www.theguardian.com/technology/2019/apr/20/fake-reviews-how-the-facebook-factories-are-still-ripping-us-off

Months after a Which? investigation into the manufacture of misleading reviews on Amazon, most are still active

Consumers continue to risk being ripped off as a result of fake review “factories” on Facebook that manufacture misleading Amazon product reviews, says Which? It told Guardian Money that “nearly all” of the Facebook groups it uncovered last autumn were still active this month.