The Prohibition Causes an Abusive Behaviour among the Users

Since drugs are illegal and using them can jail a person, drug users usually exhibit abusive behaviours: they lie, steal, and become dishonest and suspicious. This is not an effect of the drug itself - it's a result of the psychological and legal situation in which they are present. By legalising drugs, one can be sure that drug users will be able to openly admit their problems, and seek help.