A new study by U.K-based consumer watchdog Which? analyzed thousands of listings and discovered how far some vendors on the world’s biggest shopping website go to mislead customers. It probed the top 20 products in popular home technology categories—and found a slew of abusive tactics.

In one case, the researchers said a customer had received eight requests from a seller to alter a 3-star rating to a 5-star rating on a solar floodlight product, even offering a partial refund in exchange.

Natalie Hitchins, the group’s head of home products and services, said: “Our investigation shows the lengths that unscrupulous sellers will go to constantly pull the wool over the eyes of shoppers.

“It is unacceptable that consumers continue to be misled into buying poor quality or even unsafe products by the current system of reviews and rankings,” Hitchins continued, noting the culprits could face legal trouble. “Online platforms must do more to tackle fake reviews, going above and beyond the current approach.”

In one example, the Which? researchers found a smartwatch with a whopping 938 reviews dating back to 2011—even though the product only came out in January this year. In another, reviews for a pair of headphones had been boosted by reviews intended for a soap dispenser and phone screen cover.

The firm said: “Even one inauthentic review is one too many. We have clear… guidelines for both reviewers and selling partners and we suspend, ban, and take legal action on those who violate our policies.

“We estimate more than 90 percent of inauthentic reviews are computer-generated, and we use machine learning technology to analyze all incoming and existing reviews 24/7 and block or remove inauthentic reviews.

“Our team investigates suspect reviews, works with social media sites to stop inauthentic reviews at the source, pursues legal action to stop offenders from planning review abuse, and feeds new information into our system so it continues to become more effective in catching abuse.”