We have an alert for all of us who look to online reviews before we buy a product or head to a restaurant. It turns out many of the reviews are fake. And one state is cracking down hard on the fraud.... See More
We have an alert for all of us who look to online reviews before we buy a product or head to a restaurant. It turns out many of the reviews are fake. And one state is cracking down hard on the fraud. Rebecca jarvis is here. That website, yelp, is under fire. Reporter: Yelp, citi search, even yahoo! All are rooting out the con artists online. And if you wondered whether that gushing review for a restaurant or a hairdresser is real? Some confirmation, your instincts are right on-point. They're the opinions millions of americans trust for everything from planning a vacation to choosing a dentist. But this morning, for the first time, the government says many online reviews are nothing but complete fabrication. In some cases, they went as far away as eastern europe and bangladesh to hire phony reviewers. This is a massive fraud that we're determined to shut down. Reporter: The new york attorney general is fining 19 companies $350,000 in total, fines ranging from $2,500 to just under $100,000 for paying people to write phony internet reviews of companies and products they've never even heard of. Kathy says companies like this pay her 4 bucks a pop to file reviews from her parents' home in wisconsin. They were on time. They started working right away. And in a few hours later, I had a beautiful bathroom and tile. I love it. Reporter: Have you ever renovated a bathroom? No. I'm 17. Reporter: Today, as many as 30% of all online reviews for some products are fakes. With people getting paid anywhere from $3 to $50 to write them. At the old days, we would look at advertising, talk to our friends, get recommendations. Today, this is how consumers make their choices. Reporter: Even websites like yelp, that have rules to keep the cons out, say it's a difficult battle. We've seen studies that a one-star increase on yelp can increase a restaurant's revenues by almost 10%. Reporter: New york's attorney general tells abc news this morning, a number of other states are also conducting their own investigations into fraudulent reviews online. So, even though this is a new problem, the same old rules apply. Buyer beware. Anyone can write any kind of review. But it's a company and that's where the problem comes. Reporter: The company paying people to write the fake reviews. THAT'S WHERE THE A.G.s ARE GOING After. And you might see similar states going down. Something online, not true? How can it be? How can it be? Thanks a lot for bringing that to us.
This transcript has been automatically generated and may not be 100% accurate.