Negative Yelp reviews continue to climb about a Manhattan dentist who allegedly charged her patient for giving her one bad review on Yelp.

Dentist Stacy Makhnevich, who also holds a second job as an opera singer, is being sued in a Manhattan Federal Court by former patient Robert Lee for trying to prevent him from criticizing her on Yelp.

According to the lawsuit that was filed on Tuesday, Lee claimed that the dentist forced him to sign an agreement that he wouldn’t write negative comments about her online before she worked on his teeth.

After she allegedly overbilled him by $4,000 dollars Lee criticized her on the business review website,

“Avoid at all cost!” Lee said of Makhnevich, according to his Yelp post.

“Scamming their customers!”

Kellie C. of San Diego, CA said on Yelp that she has been in the dentist business for almost 12 years and opined that Makhnevich had overcharged Lee.

“From what the patient wrote, it's my understanding he just had his tooth drained and a filling? Maybe a temporary filling? Or a root canal….Either way 4,000 dollars? Maybe for an implant. Shame on her.”

Lee alleges that the dentist began charging him $100 dollars a day for each day the posting remained online.

The dentist, punishing the man for one bad Yelp review now has hundreds of reviews on her site from across the country.

“I hope you learned a good lesson from all this. He left you one bad review. How many bad reviews do you have now? Can you count them?” writes Naomi G. of Renton, WA.

John A. of Los Angeles, CA along with many others said on Yelp that making patients sign a contract to not post negative comments is “unethical.”

Some gave Yelp credit for exposing negative reviews about other people and places as it helps the viewer make a decision on where or who to go to.

“Reading upon what you did to your patient was totally unethical and unprofessional. I hope your store will go out of business. Also, I applaud Yelp for exposing people like yourself,” said Man Yee C. of Mississauga, ON.