Just about anyone knows that a particularly bad online review could make or break a restaurant.  But can the possibility of negative review be a vehicle for extortion?

That's what Sonny Mayugba, co-owner of the Red Rabbit Kitchen and Bar in Sacramento, Calif. says happened when a man claiming he got food poisoning after eating at his restaurant threatened to write a "scathing" review on Yelp unless Mayugba gave him a $100 gift card.

Mayugba told The Sacramento Bee that it was impossible to prove whether the man got food poisoning from the restaurant, but offered to give him a $60 gift card for his trouble. But the man reportedly said he wanted $100 and said if he didn't get paid, he'd also report the eatery to the health authorities.

In the end, Sacramento Bee reported that Mayugba refused to give the man anything.

But other restaurant owners claim that the threat of bad online reviews are being used to intimate them. Some even have a policy to try and nip them in the bud. DeVere’s Irish Pub in Sacramento told CBS that the restaurant has a policy of, "help us before you Yelp us," and asks patrons to approach management before posting an angry rant on the site.

This isn't the first time that Yelp has been in the center of controversy.

Back in April 2010 several business owners accused Yelp of extortion, saying after they refused to advertise on the site, it promoted bad reviews of their establishments. The case was later thrown out, but these incidents raise questions about the accuracy of Yelp and other review sites. Yelp says they filter out spam-like posts, but the site also uses a closely guarded algorithm to decide which reviews are prominently seen and which are buried.

Tell us if you've been the victim of Yelp extortion.