Amazon announces new technology to fight fake user reviews

NEW YORK -- Online shoppers may have to think twice about those five-star ratings, because many of them are fake.

But Amazon is cracking down, using a high-tech tool to weed out phony reviews and make sure customers are not duped.

Fake user reviews: it's an epidemic online that's eroding consumer confidence. To fight it, Amazon just announced new, sophisticated bots that will comb these write-ups looking for reviews that aren't real.

"We will use software to lower the rank of reviews that don't match purchase history and that are voted down by readers," the company said in a statement.

In April, Amazon sued four companies that were writing fake reviews to help sell more products ,and New York imposed fines on 19 businesses that sold fraudulent testimonials and posted them on Yelp and City Search.

Savvy consumers are catching on, and say they have seen reviews that look fishy, too specifically glowing or too general.

So how easy is it to post a fake review online? ABC News' Becky Worley did it in less than a minute.

According to Business Insider, user reviews are essential to the online economy - sites like Airbnb, Yelp, and Ebay rely on them - but some estimates put up to 20 percent of reviews as fake.

"It is incredibly important that the reviews be credible," Ashley Lutz, Business Insider retail editor said. "This is a huge advantage that Amazon and other retailers have over, you know, the physical store."

That means technology that makes reviews more trustworthy could be a game-changer for the internet.