Yancy's Saloon
Yancy's Saloon is a bar in San Francisco that is run by extortionists. It is the absolute worst bar you could ever hope to go to, especially if you wish to film an episode of Scam School.
Brian had booked an episode of Scam School to be filmed at this location on July 30, 2010. After they had started filming, Alan the bartender squeezed Brian for more cash. When Brian told him that they had no more cash, they were thrown out "with EXTREME prejudice!"
Following that, Brian sent out a tweet, alerting the demon hordes to the incident, linked to the bar's review page on Yelp, and said "you know what to do."
They did. In a period of several hours, dozens and dozens of negative reviews were left on Yelp. The venue's pages on Foursquare and Gowalla were also modified.