Wang, a vagrant, holds up his handmade "porn spot map" for a reporter during an interview. [Photo/Guangzhou Daily]

A vagrant surnamed Wang provided his self-made "porn spot map" to Dongguan police based on his own investigation, helping the police in their work, the Guangzhou Daily reported Tuesday.

Local police has launched a three day anti-porn campaign since May 24.

A total of 1,148 people were caught, and 30 porn-related businesses were busted by Dongguan police in a three-day period, according to the report.