So, was it 30 to 40, 40 to 50, or around 100? Depends which report you read on the numbers. I reckon Melbourne is just missing the traditional gangs that used to be common down there. Like the Asian Gangs and the Middle Eastern gangs in the 80's and 90's, or even the OMCs that you don't really see much in the paper about anymore (Gee they must have all disappeared). So now, any large group of similar looking people (age, race or dress) has to have the "gang" identity, and the "gang violence" theme promoted, or it won't sell papers.
Bring back the good old days of the Sharpies, the Rockers and Bodgies etc..