That's a terrible predicament. It's not true to say the law only protects the dirtbags, but it is frustrating that there seems little one can do without breaking the law oneself.
We had dealers living on both sides of our house, though they weren't a menace at all, in fact I got along quite well with them. One family was particularly kind to my eldest daughter, but things went bad all of a sudden and they bailed out, so we moved next door into the place they'd left. A few weeks later the cops turned up looking for the previous occupants... He's now doing ~20 years for cooking meth.
We still live there, and the other one has reformed apparently, is still mates with another neighbour. I used to dream about lifting a roof tile and finding stacks of cash hidden there.