I agree rangrz but in response to this:
I would say that's not surprising if most of them don't have a background in medicine/science. In addition, its schedule 1 status precludes it from going through the same route of approval by the FDA (in the US) as other drugs. So unfortunately many have to rely on a (rather large) body of anecdotal literature instead. If the toxicity profile were no so low in comparison to many OTC medicines this would be a major issue but fortunately for many illnesses the potential benefits of a positive outcome received from trialing the drug outweigh any possible side effects of the drug. The downside is that there is the risk of it being oversold, perhaps even for minor conditions that could easily be treated successfully through other means and dare I say this is the situation we are in, with many people viewing it as a medical panacea when it clearly is not. Rick Simpson and his run from the cure video is a prime example of this.
Until things change we're in a catch-22; major research into therapeutic uses of the herb is unlikely to be done until it's removed from its schedule 1 status and the government is unlikely to move it down to schedule 2 or 3 until more promising research into it's medicinal use is made available. Of course they purposefully like maintaining the status quo but that's another discussion entirely.
But just because they don't have the background to give it a rigorous treatment does not mean that methodologically flawed information suddenly becomes credible.
On a certain level, many of the, erm, I'll be VERY generous and call them case reports, are flawed in a way that exceeds simply not having a deep background in medicine. It is to the point of not having a background in either logic or reality.
What do I mean? One of them is a tendency to use the naturalistic fallacy. "Because cannabis is natural, it is therefore good, or at least not bad, on that simple fact." It takes very little familiarity with the general tenants of modern medicine see why that just ain't so. I don't mean having university studies in the life sciences, I mean having read a few newspapers, gone to high-school or otherwise having the general notion of things like "Bacteria and Viruses can be infectious!" or "Some types of mushrooms and even rocks are quite poisonous." type of understanding. That refutes on a logical level, the concept that "natural=good". The empirical support for cannabis specifically is now a separate issue and not realizing that requires one to be a) unable to use basic logic or b) having deluded oneself to a very deep level.
Post Hoc Ergo Propter Hoc. "I smoked cannabis and then I got less sick; therefore the cannabis was the cause of that." I once ate a hamburger about half an hour before a solar proton event, therefore; eating hamburgers causes the Sun to eject mass from itself in abnormally violent manner.
Argument to (inappropriate) authority. A quote from a musician, athlete, political activist, or even a random scientist with no relation to biology or medicine[I dunno, like a semi-conductor engineer or a geochemist) is not really much of an argument in favor of it's medicinal properties, and this should, imo, be evident to someone without a science background.
The last one. If you clearly have no idea what the hell you are saying even means, you probably have nothing of value to add. Case in point, I was talking to someone at headshop, and they where saying cannabis is an immune simulator. I asked them "Like how/in what way?" and they gave me VERY jargony reply that amounted to "It mimics the effect of Granulocyte colony stimulating factor." I was intrigued by that by and asked what effects it had on lymphocytes and monocytes, if any. They gave me a blank look and upon pressing, they stated they don't know what any of those are and that they read it on a blog. ... If you don't even know what the words mean, it should be apparent you don't know the hell you are talking about.
Etc...
That no research exists on cannabis as a medicine/ or in bioscience fields in general? Not true, there is a HUGE body of scientific literature on Cannabis. Google scholar has 34,000 results for "cannabis therapeutic" and over 70,000 for "cannabis medical" and 101,000 for "marijuana medical" [vs 48,000 for sirolimus a somewhat obscure but approved and non-controlled drug that is more interesting on a biological level] many of them in very prestigious journals like The Lancet, Nature, Journ Amer Med Ass. Granted, the text is dense, verbose and does require a familiarity with medicine/biology on some level and more generally how to read scientific journals. Yes, most of the articles are likely to be quite irrelevant to anyone not in a specialized research field...but there are a lot of of them that are quite relevant to actual, real life, clinical use. Hell, as far as science journal articles go, medicine is probably one of the easiest and most understandable[compare to particle physics for e.g.], and the ones on cannabis seem less jargon filled and complex then most medicine papers.[compare to electrophysiology for e.g. ]
The SCI thing probably is not as big a deal as one might think. Being scheduled seems to be relatively small impediment to serious research, and a lot of research is done elsewhere in any event.
Sorry for the long post, but medical cannabis is an area that is subject to so much "woo" that I cringe and wince. I think the woo does harm to both medical legalization and recreational legalization because it makes the entire topic look silly. Part of that woo is extending legitimate medical research into reasons why recreational use is not only not a bad thing/something people should be allowed on basic freedoms ground into "It's like totally awesome for you because in vitro it inhibits a certain protein synthesis in astrocyte glioblastoma cell lines!" Either misunderstanding the concept/meaning or else using it explicitly or implicitly (to deal with cognitive dissonance on using recreational drugs) in a deceitful manner.
I'll STFU now.