Weird but not rare, I have seen it with gangs in Phoenix, one decided to use the number 602 as in one of the telephone codes in the area. It lasted until the police began to tell the public to watch for the ones wearing that number. Then I noticed a gang starting to use the diamond motif in a few schools I work or help.
Harder to look as worrisome or to be considered a code because the local baseball team are the Diamond Backs and the prevalence of Jewelers like Jared (He went to the president 
] or the [del]Shame[/del] Shane company. Still it was hard to miss when students or groups of youths doing dubious things began to wear clothing with diamonds shown prominently. It also stopped to the expected random levels after the police also reported the attempted copping of the word/symbol. It is clear to me that the idea is to pass their group allegiances under the radar of parents and teachers, it works and sometimes for a long time.
The reason why this is done has another benefit for the gangs, sometimes it can be turned around to get a group like the conservative media to unwillingly support the ones copping a symbol. I do remember how there was a group that in a Cinco de Mayo school celebration was busted for “just” wearing the American Flag and the conservative media ran with the narrative that the kids needed to be commended and not suspended as it was framed as “hey this is America not Mexico! The bullies have a right!” that was a good point but it missed a ton of context, as I found when I did investigate the images used: