For decades, perhaps even centuries, people have relied on word of mouth when it comes to recommendations for goods and services.

In the 21st Century, crowdsourced sites like Tripadvisor, Yelp, and Google have become clearinghouses for user reviews, helping to steer us to everything from hair salons and hardware stores to martini bars and medical practitioners.

But how much can we really trust the reviews we seem to live by?

Recently, restaurants across the nation have been hit with a cyber blackmail scheme wherein one-star reviews are posted on Google. In many such instances, the negative review is followed by an email demanding payment in exchange for deletion. A New York Times story earlier this week reported that restaurants that have received Michelin ratings might be targets.

That indeed appears to be the case in Miami, where several local restaurants that recently received Michelin recognition have seen suspect one-star Google reviews — and the subsequent shakedown emails.

Grove Bay Hospitality Group CEO and cofounder Francesco Balli says Stubborn Seed, which was awarded a Michelin star last month, received the following email:

Hello. Unfortunately, negative feedback about your establishment has been left by us. And will appear in the future, one review a day. We sincerely apologize for our actions, and would not want to harm your business, but we have no other choice. The fact is that we live in India and see no other way to survive.

We are begging you to send us google play gift card worth $75

You can buy the card directly from PayPal

paypal.com/us/gifts/brands/google-play

Or in any store selling gift cards

We hope that this amount will not be critical for you.

After selling this gift card we can earn approximately $50, which is three weeks of income for one family

Please send the code to the email address [email protected] and we will immediately stop leaving negative feedback and remove the existing ones.

Once again, we apologize.

Balli immediately took action. "The email was clearly spam, so we deleted it," he tells New Times. "It's a shame that restaurants are being targeted in this way. I think most diners are savvy enough to read past these fake Google reviews and can identify which ones are clearly bots versus real people."

Niven Patel, partner at Alpareno Restaurant Group, says his management team alerted him that his Coral Gables restaurant, Mamey, was hit with a slew of one-star Google reviews, starting about a week ago. Most of the reviewers, he says, had no review history on Google. Some had geolocations thousands of miles from Miami. "I'm sure they're coming from overseas," says Patel, who hasn't received any extortionate emails.

Although Patel is convinced the reviews aren't legitimate, he still worries. "Reviews are still very powerful, even to locals," he notes, adding, "It not only affects guests, but potential investors put a lot of weight into reviews."

Patel tried to get in touch with Google, to no avail. "We can't speak with a real-life person. And although the reviews are obviously very fraudulent, Google auto-replied that they meet the company's criteria," he says.

Patel's other restaurants, Ghee Indian Kitchen and Orno (both included in the Michelin Guide), have not been affected.

Fellow Michelin star recipient Cote Miami has been hit by one-star Google ratings as well. The restaurant's social-marketing team has taken a proactive approach, looking up the names of the reviewers to see if they matched customers who made reservations, then posting a reply.

One such response: "Thank you for reviewing us, I have tried to reach you out but unfortunately, I was not able to locate your information in our reservation platforms, we would love to hear more about your experience with us and what we have missed through your dining experience, please email us from [email protected] and we love to make it right and earn your trust. Looking forward to hearing back from you. Sincerely, Cote Miami Management."

Reached by New Times, Cote Miami declined to elaborate on its dealings with one-star reviewers.

Ariete and Boia De —both Michelin star recipients — were also targeted in the scheme, according to the Miami Herald.

Posting negative reviews and then demanding remuneration for their deletion is considered a cybercrime, cybersecurity consultant Alan B. Watkins told the New York Times, which noted that law enforcement is encouraging restaurant owners not to respond to the blackmailers but to contact the Federal Bureau of Investigation and the Federal Trade Commission instead.

Consumers can help to deter extortionate cybercrimes through basic due diligence. When using online resources such as Google or Yelp in making a decision, consider the source: Does the reviewer have a history of other reviews? If they had a grievance, did they cite specifics regarding the quality of goods or services? (There's also the old-fashioned route: Ask friends for recommendations or consult trusted media sources, like this one!)

And if you personally have beef with a restaurant and want to go public, state your case clearly.

Grove Bay's Francesco Balli says his company tries to vet all online reviews and welcomes genuine customer feedback.

"Whenever we receive a legitimate review that talks about a less-than-great experience we take that seriously and work to remedy the situation. Our team will contact the guest directly and ask to learn more so we can make things right. What these review scammers are doing is not legit, and it's a shame they're targeting restaurants with this hack."