Some of the most used platforms for travel and online shopping said Tuesday they’re going to team up to battle fake reviews.

Amazon, reviews site Glassdoor and Trustpilot as well as travel companies Expedia Group, Booking.com and Tripadvisor said in an announcement they’re launching a coalition that aims to protect access to “trustworthy consumer reviews” worldwide.

The companies said the members of the group, which will be called Coalition for Trusted Reviews, will look for best practices for hosting online reviews and share methods on how to detect fake ones. That will include developing standards for what constitutes a fake review and sharing information about how bad actors operate.

Phony reviews have long plagued online marketplaces despite their efforts to eradicate it. Much of the problem is fueled by brokers who solicit fake customer reviews through social media platforms, encrypted messaging apps and other channels in exchange for money, free items or other benefits. Brokers can solicit positive reviews to boost sales for businesses or sellers. They can also also post negative reviews for competitors in order to tank their sales.

Last month, Amazon said two review brokers in China were sentenced to two-and-a-half years in prison and three years of probation after using messaging apps to advertise and sell fake reviews to Amazon selling accounts. The company has filed a flurry of other lawsuits in the past year against operators that it says were doing similar things. Last year, it also sued the administrators of more than 10,000 Facebook groups that it alleged were coordinating bogus reviews in exchange for money or free products.

Facebook groups trading reviews for Google and Trustpilot, which allows users to leave feedback for businesses, were also discovered earlier this year by the British consumer watchdog group “Which?”

Federal regulators have also been aiming to crack down on bogus reviews aiming to deceive consumers. In June, the Federal Trade Commission proposed a new rule that, among other things, would prohibit businesses from selling or obtaining fake reviews, suppressing honest reviews and selling fake social media engagement.

Businesses would also be prohibited from creating or controlling a website that claims to provide independent opinions about its products and employing other practices like “review hijacking,” which makes reviews for one product appear like they were written for different ones. If the proposal is adopted, violators can be face penalties.

Becky Foley, Tripadvisor’s vice president for Trust & Safety, said in a statement included in the news release that combating operators behind fake reviews will be “an immediate area of focus” for the coalition.

“These actors often operate outside of jurisdictions with a legal framework to shut down fraudulent activity, making robust cooperation even more important,” Foley said.

The companies said the coalition is a result conversations that came out of a “Fake Reviews” conference that was organized by Tripadvisor and held last year in San Francisco. They said they will meet in early December at a second conference that will be organized by Amazon and held in Brussels.

(AP)