that style of bag because in the UK it's a drug dealer, urban youth thing
A "shotta bag", ha. But those are the more single small pouch things with a strap. They're perfect because they keep your bits and pieces away from your body heat. If it's weed you're selling better for it not to be in your pockets cos the warmer it gets the smellier it gets. Don't want your clothes smelling either. If it's white you're selling then that gets oily if it gets warm against your body so best to keep it in a bag. These bags are small and really easy to swing round by the strap and throw. You can throw them up into a tree or onto a building for retrieval later if you need.