I've heard of places where HR requires you to write a (probably) glowing Glassdoor review during onboarding. Or severance which is conditioned on not writing a negative review.

Goodhart's Law at work.

Easy enough: Write the glowing review, then contact Glassdoor and report your company. I'm fairly sure Glassdoor would then remove all the reviews.

No, they'd offer the company to remove the negative review for a fee.

Write a good review, receive your severance and then change it to a negative review.

In some countries the law specifically mentions that such terms of severance agreement is not valid and cannot be enforced.

Someone posted a similar comment on the work-life balance post.

I don't see how this works at all except at the bottom level.

If I read that your salary is X, and interview, I expect that the negotiation revolves roughly around X.

If you offer me 0.7*X I'm going to walk and I expect anyone qualified would.

I think what GP means is that the employer gives X to current employees, but makes false posts on this website, that claims there are employees that make 0.7X. Then when you interview with the employer, they offer you X, and you think you are being offered 30% more than your future co-workers, so you happily take the job.

(minor niggle) x is about 42% more than 0.7x, not 30% more.

I verify manually that person’s data (job title, company name, and location) matches what they have on their LinkedIn profile as a current role.