I have a friend who I often chat about job searching with (we're both on the market). They recently had a shockingly bad experiece with a company that prides it

I have a friend who I often chat about job searching with (we're both on the market). They recently had a shockingly bad experiece with a company that prides itself by it's glassdoor rating. They told me they don't plan on writing a review, because they're worried said company may intuit who wrote they review and blacklist them from future hiring. They insist they must have had an outlier experience. I can see how this attitude in aggregate, coupled with NDAs laden hush money leads to an inaccurate picture...