Needle exchanges allow anyone who used the medical equipment to take them to an exchange center and turn in their used needles. Without that ability, the community at large would have to find a way to deal with mass levels of blood-borne biohazards that could or could not spur mass spread of viruses and diseases alike. They are absolutely needed and a benefit in EVERY community
Needle exchanges is something that is truly not a good idea, I feel that this would only have people who are drug addicts, to crave into their addictions and never get the help they need. I understand that people would want addicts to at least use clean needles, so the spread of diseases doesn't happen, yet what you're doing with this program, is seemly having drugs to stay high and only coming to those programs to get those needles for their drug addiction. It's just a lose-lose situation, the best thing to do is to just have programs to help addicts with recovery.