The Beijing population of "Chaoyang mass" has reached 140,000 in 2017, people.com.cn reported Sunday.
Chaoyang mass literally refers to residents of Beijing's Chaoyang district, who are dubbed the "fifth-largest intelligence agency" in the world for tipping off police about suspected drug dealers and helping catch criminal suspects.
That translates to an average of 300 Chaoyang mass per square kilometer.
The report said the number of those who have close interaction with the local police in Chaoyang district has reached 70,000, who provide an average of 20,000 tips on offenses such as stealing electronic bicycles, pickpocketing and suspected drug deals.
Chaoyang police received about 8,300 valuable tips in 2017, leading to 370 cases with over 250 suspects detained and 390 potential safety hazards cleared up, according to the report.
A smart phone app called "Chaoyang mass" was launched by Beijing's Municipal Public Security Bureau in March 2017, through which district residents can submit tips to the police.
Elite tipsters can earn 300 to 500 yuan ($45 to $76) as a reward.
