Since then, a one-star review on Yelp.com shows up first when you search the company, and it calls owner Michael Rassel a “scam liar and complete weirdo.”

So this month, Rassel filed a defamation lawsuit against the customer, Roy Gonzales, bringing to Sarasota a growing threat that a critical review can land disgruntled customers in court.

More and more people are using the Internet to research companies and to post reviews — praise or grievances, justly or unjustly — that can reach potential customers on a wide scale.

But few realize it could cost them, as more businesses use lawsuits to fight back, says Marc Randazza, a Las Vegas attorney who defends online defamation cases in Florida and across the nation.

“The day you get served with a defamation suit, whether you’re right or wrong, you just lost $20,000 minimum,” Randazza said. “Most defamation defendants are blindsided by it.”

Defamation suits to silence online critics have increased in Florida since 2008, when a Florida Supreme Court ruling and a lack of a law protecting consumers makes suits harder and more costly to defend, Randazza said.

In the Sarasota case, Rassel says the rants against him are flat out wrong, an attempt from the customer to pressure him into doing extra work for free.

But Rassel also says the one man’s reviews are killing business for him — a 70 percent drop in income.

“They see something like this on the first page of Google, they’re gone, they’re not even going to give me a second thought,” Rassel said.

And there is another entry on ripoffreport.com from the same disgruntled customer, calling Rassel a “low-life cheat” and implores readers not to hire him.

The impact was immediate, Rassel says. Potential clients started disappearing, clients that were lined up prior to the rant suddenly changed their mind.

“My business has been violated,” Rassel said. “I’ve spent 10 years building this business locally, for someone like this to just come along and post something that sounds like a drunken sailor.”

Gonzales could not be reached for comment on his comments or the lawsuits. His Yelp.com profile shows he has written hyper-critical reviews of two other companies, a Fort Myers car dealership and an insurance company. Each time he begs readers to stay away.

Gonzales does have one positive review, however, saying his wife likes the salads at Rico’s Pizza in Sarasota.

To be defamation in Florida, the review must not be an opinion, but include facts that are untrue and damaging to someone’s reputation, said Sarasota attorney Robert Turffs, who is representing Rassel.

“You can say I didn’t like him, he did a lousy job, you can say that all day long,” Turffs said. “Once you say this guy took money from me and didn’t perform, that’s a lie.”

Companies like Yelp are protected from lawsuits because they are providing a platform. It is the reviewer who is responsible for what is said, attorneys say.

Yelp asks reviewers to write honestly and stand behind their reviews, and tells businesses to engage constructively with customers who have not had a positive experience.

A Yelp spokesperson said the company expects “users to feel free to air their opinions, but not to exaggerate or misrepresent their experiences.”