Yelpers
Yelp is a website where people can create reviews on local businesses. The website exists in real life as well.
Background[]
In "You're Not Yelping", Yelpers intimidate restaurant owners with the threat of a 1-star review after being denied special treatment. In response to the many negative reviews, the restaurant owners kick out yelpers. The Yelpers respond with extreme violence, led by Cartman. Kyle and Cartman eventually find a solution, tricking the Yelpers into believing that each of them are the lead Yelper. When the restaurant owners finally let the Yelpers back in, they deface their meals with bodily fluids.
Yelp is also mentioned in the Season Nineteen episode "Safe Space", when Cartman asks Butters for a paper copy of his Yelp, and social media comments.