Yes, but aren't there two separate issues here:
1) Chaotic drug users travelling between sites like Brixton and Camden in search of harder drugs. Often heavily addicted, in need of help and likely to be involved in crime of some sort to fund their (very) regular habit.
2) Opportunistic purchasers trying their luck purchasing recreational drugs around Brixton (generally weed). Perhaps middle-class locals or visitors, unlikely to have to steal to fund their occasional visit. Unlikely to be the ones shouting abuse down Rushcroft Road at 4am in the morning and shitting in gardens.
The thing which potentially annoys me about the way this police initiative is presented is that the aim seems to be to crack down on the second group to make an example, giving the bizarre reasoning that it may affect the first
They're easier targets for sure, but it strikes me as a cowardly white flag from the police - as if they find it too unpleasant to tackle the harder users (who most need help) and properly take on the worst of the dealers and thus want a simpler, press-friendly option. It fails on so many levels for me - occasional purchasers are unlikely to hear about this initiative and be discouraged from buying. And, put mildly, the dealers are unlikely to give a shite whether their punters are getting arrested or not - hell, the ones that sell oregano/oxo whatever may even be glad of the distraction.
Crap window dressing rather than effective policy imo...