I would add to that 'in the predominantly black areas'.
Back in the mid 80's I lived on the outskirts of Peckham, South London, and noticed a sudden and marked growth in ownership of pit bulls, not only by black people but whites as well. Mostly younger lads about 18 - 25, some older, but obviously bought to enhance their 'street cred'.
I recall being out shopping with the wife in Rye Lane, and went into the covered market. Whilst she was shopping I stood away and noticed a young black lad standing there with his chest puffed out, arm outstretched holding a lead with a cracking young pit