This is untrue, no matter what Yelp says about it. I used to run a small business. We had small-town drama, and some left a review saying we gave them food poisoning (we did not serve food of any kind). Yelp refused to take down the review for over a year. Then a salesman called, offering advertising, and we said Well gee, we'd love to, but this review... and it was gone. We didn't even have to pay for advertising, just had to play hard to get with the sales guy.