An Orlando plastic surgeon's defamation lawsuit against a patient could be a sign of legal struggles that will test the boundaries of freedom of speech as rating sites flourish on the Internet.

Domingo Rivera, attorney for Dr. Armando Soto, said the patient's comments on RateMDs.com are not opinions protected by the First Amendment but a "malicious campaign of unlawfully defaming and spreading lies" about his client and business.

But the lawyer representing the patient, whose name is not in the lawsuit, warned that the suit could have a chilling effect on users of sites such as Angie's List, Vitals and others that rate professionals and services.

"The terror created by this lawsuit will squelch freedom of speech," said David Muraskin, a Public Citizen attorney representing Soto's critic.

The anonymous online comments were posted on RateMDs.com in 2011 about breast-augmentation surgeries that the patient contends Soto botched.

Rivera said comments stating that the "end result is horrible" and "Dr. Soto did a poor job" are opinions. But comments about unevenness, extra scarring and other issues are defamatory because they aren't true, he said.

"If a patient is unhappy, they can use constructive criticism, or return to the surgeon to fix it," Rivera said. "This person has a vendetta, and my client has to use the court system to remedy that."

Rivera originally filed the suit in December in a Virginia court because his client believed the patient who posted the online complaints might be in that state.

The Henrico County Circuit Court granted Soto a subpoena in April to force Comcast of Georgia/Virginia to divulge the Internet IP address, identity, mailing and billing addresses of the person who posted the comment.

Rivera said he most likely will drop that subpoena because he has independently learned that the patient is a schoolteacher in Osceola County, Fla. He suspects she has posted comments on the website, posing as another unhappy patient.

Rivera said Soto wants the posts removed and is seeking $49,000 in damages.

Markita Cooper, associate dean at Florida A&M University's College of Law, said cases like these pop up because most people don't know the difference between opinion and defamatory speech and some "courts struggle with it from time to time."

"The more figurative, colorful, and hyperbolic the speech, the more likely it is not liable," Cooper said. "But when the opinion becomes a factual statement, then you are dealing in some murky areas."

Cooper said anonymity is a problem for service providers, because there is no one to hold accountable for the comments and they can't always force the Internet provider to divulge the identity of the posters.

She added that most people have "gotten comfortable with expressing themselves online" and doubts these types of lawsuits will have a major effect on freedom of speech, unless a highly publicized case draws attention to the issue.

The Communications Decency Act of 1996 grants immunity against lawsuits to most rating sites themselves, stating that "no provider or user of an interactive computer service shall be treated as the publisher or speaker of any information provided by another information content provider."

Some rating sites, such as Angie's List, which rates contractors and other household-service providers, avoid the pitfalls linked to anonymous posters by registering all their users.

"We expect our Angie's List members to tell us a truthful account or experience," said Cheryl Reed of Angie's List. "We also remind our members that their identities will be known if that person or company asks."