We have quite a long garden that backs onto a scrubby bit of public land (full of overgrown bushes and trees) that the local druggies like to use to shoot up in as its out of the way of public view.
As soon as the sun comes out its like a conveyor belt, groups of 4 or 5 at a time doing their stuff and leaving dirty needles, bits of foil and other drug stuff behind. I recognise most of them now, they come from the direction of an alcohol/drug dry centre a few roads away, this is the nearest bit of public land to them.
I hate going up the garden during sunny times as you can guarantee someone will be there, you can hear the foul language over the fence. Luckily DD is too little to understand it but in the summer it affects our use of the garden and I'm fed up with not wanting to use some of my own home because of them.
If I know they're up there I ring 101 and usually a PCSO will go and take a look, but by that point they are usually gone. I've been told by the coppers that if they see them they move them on but otherwise there's nothing they can do.
It really makes me 
when I see the same people begging for money on our high street. It isn't hard to see where the money goes.
And before anyone says, no I don't want them just to be 'moved on' to be someone else's problem, I'm just frustrated with the effect it has on our living space. It must be terrible to have a drug habit when you do that kind of thing to yourself.