The problem still persists. You can't talk about spending government aid on drugs without addressing drug use as the two are correlated. So what, you find a way to stop them from spending government aid and then what?
So if a person catches a drug case because he spent his own $20 on a crack rock, and has no money to afford a lawyer, you're saying he shouldn't be given a PD? So where would that leave PD's?
So what exactly is your point here? You say you agree that it would be nearly impossible to effectively control this, and say it would create a shift in spending habits and creation of bartering drug trade, but you forget that the problem still persists. So in essence, the fiend will spend the money on food or other tangibles and spend trade those goods for drugs. So what is the problem here that needs to be addressed? Should we seek to reduce the drug problem or should we seek to control spending habits by offering drug tests?
Logic my friend....