It is certainly not morally beyond the feds to kill heroin users. After all, during Prohibition, they distributed poisoned alcohol to punish drinkers, and murdered thousands.
UPDATE from Phillip Osborn:
4:12 pm on February 9, 2014 Email Llewellyn H. Rockwell, Jr.
The feds are already poisoning prescription opiates by insisting they beblended with acetaminophen, which causes liver damage.