He did it so that he could report them, btw.
Just to make that part 100% clear.
The man was walking when he saw an immigrant pee in broad daylight, in the middle of the road, and heedless of passers-by.
The young doctor from Treviso decided to photograph the boy to report the incident to the traffic wardens, but the four friends who were with the ‘piscione’ noticed the photo taken and started to pursue him in a threatening way.
The doctor was stopped shortly after and slammed violently against a wall. Wrenched and kicked, he managed to wriggle away and immediately called the police to his rescue but the phone call made his attackers even more furious, and they continued to threaten him in broad daylight and in the middle of the road.
The gang only moved away when a police car arrived at the scene.