If you are saying addicts commit crimes e.g. burglary well then prosecute them for those crimes, that’s the only way I can take the “blight on their surroundings. Taken a different way, there are a lot of humans in the us who use other drugs, alcohol e.g. who are not considered a blight on their surroundings. Street drugs could be like those drug, and in fact during prohibition alcohol was an illegal “street” drug.