...said the court, rights are contingent upon responsibility. If a chimp can’t be expected to fulfill his social duties, neither can he have rights.
“Unlike human beings, chimpanzees cannot bear any legal duties, submit to societal responsibilities or be held legally accountable for their actions,” wrote the judges.
“In our view, it is this incapability to bear any legal responsibilities and societal duties that renders it inappropriate to confer upon chimpanzees the legal rights—such as the fundamental right to liberty protected by the writ of habeas corpus—that have been afforded to human beings,” they concluded.
But as a proportion of the (dropping) violence, you're right - more are more is drug related.
Nothing new about that - in the US nearly half of all prisoners are incarcerated on drug charges.
Yet nobody seems to learn. The Feds just keep moving from one drug panic to the next - each time creating a new crop of black market violence and non-violent prisoners. This week it's Oxycontin - next week, something else.