Mexico enacted a controversial law today that decriminalizes possession of small amounts of marijuana, cocaine, heroin, and other drugs while encouraging government-financed treatment for addiction free of charge. The Associated Press reports that the law sets out maximum \u201cpersonal use\u201d amounts for drugs, also including LSD and methamphetamine. People detained with those quantities will no longer face criminal prosecution. Anyone caught with drug amounts under the personal-use limit will be encouraged to seek treatment, and for those caught a third time treatment is mandatory, although no penalties for non-compliance have been specified. Mexican authorities said the change only recognized the longstanding practice in Mexico of not prosecuting people caught with small amounts of drugs. The maximum amount of marijuana considered to be for \u201cpersonal use\u201d under the new law is 5 grams\u2014the equivalent of about four marijuana cigarettes. Other limits are half a gram of cocaine, 50 milligrams of heroin, 40 milligrams of methamphetamine, and 0.015 milligrams of LSD.