It's not a "feature", it's a bug!

Four features of drug prohibition:

1. Prohibition engenders criminal enterprises and criminal subcultures.
2. Prohibition generates more potent forms of the forbidden substance.
3. Prohibition enlarges drug toxicity by contamination and adulteration.
4. Those poisoned by interdicted substances in their potent or contaminated forms are blamed for their disabilities, or even their deaths, because they were engaging in outlawed conduct.