Have a look at the DEA page, what a collection of fallacies and scare tactics:
http://www.usdoj.gov/dea/concern/marijuana.html
like, "exposing the myth of smoked medical marijuana: Smoking marijuana weakens the immune system and raises the risk of lung infections"
Since when medical marijuana has to be smoked? It can be taken in so many different ways! It´s so blatantly obvious that we cannot trust what the DEA has to say about drugs because of their dependancy on anti-drug laws. That´s right, the DEA has become DEPENDANT on these unfair anti-drug laws. It developed a dependency with anti-alcohol drugs, and since "Treatment for drug dependence ... often includes administration of another drug, especially for substances that can be dangerous when abruptly discontinued", they changed to anti-marijuana prohibition to fulfill THEIR NEEDS. The symptoms of their "addiction" are the usual: Desensitization, rigid interpersonal behavior, denial...
When are people going to stop these liars to make business out of an artificially created "problem"? The biggest problem is Illegalisation itself. Even with hard drugs. Legal Morphine addicts can lead perfectly normal lives, while heroin addicts have to suffer from infections, criminalisation and all these adverse effects due to ILLEGALISATION, not caused by the drug but by the anti-drug laws!