Yelp has warned a group of California businesses that they can’t continue to write favorable reviews for each other, The Los Angeles Times reported.

According to the newspaper, the review service removed the suspect testimonials from its site and warned the “review-swapping group” against such behavior.

The group consisted of small businesses that are part of a local networking group, including a counseling center and an attorney, the paper reported.

Yelp has said it filters out fake reviews through a “proprietary algorithm.”

JCK