Meaning you were pressured by an employer? Would be interesting if Glassdoor periodically reached out to users to revise reviews and capture sentiment "before and after" working at a given company.
Glassdoor does provide the ability to review the interview process itself which somewhat fits the bill.
CEO newsletter high-lighted recent glassdoor reviews and "refuted" them internally, along with a soft recommendation to leave a good review.
Not necessarily under handed, but still gaming the system.