I witness a bloke breaking in to a car, call the Police. 20 minutes later the Police ring back saying they have caught a suspect, and ask me to describe him.
I think carefully, can I tell then he only had one leg and was wearing a kappa tracksuit, or is that discrimination against disabled people and chavs?
All the OP did was pick out a distinguishing feature of one of the culprits.
The behaviour though is just pack mentality, you see it at trails centres when people turn up with all their chums.