广州街头 (Canton: Two Thieves were caught in the market...)

The mobs take "justice" in their own hands when the government does not perform its function. Canton is famous for the thieves, muggers, prostitution and all sorts other street crimes. To be fair, most of the crimes are not done by the Canton locals but by immigrant workers from other places. When the government failed its duty to maintain the safety, angry mobs often let their anger out when they get safe chances like this.
The fact that these two thieves were caught and beaten so badly shows that they are not part of an criminal organization and not protected by the police. Otherwise, the situation could easily be the other way.