What follows is an afterthought to Syria and the right to know.
The arms channels to the FSA have been uncovered by investigators expert in identifying types of armaments. The identification process almost always involves examining uploaded YouTube videos. Naturally these videos are designed to show something of interest to potential viewers, and naturally this means they often display some novel or relatively powerful weapon.
This very likely has led to a disproportionate emphasis on novelty and quality as opposed to quantity. This emphasis runs up against the frequent assertion, from many quarters, that the rebels 'lack heavy weapons'. The experts have now observed, several times over, every type of armament the FSA needs to defeat Assad. True, there aren't any weapons effective against fixed-winged aircraft, but these aircraft are used so crudely and indiscriminately that their main effect is to slaughter civilians - militarily they're not decisive. The FSA has displayed some MANPADS models that should be very effective against helicopters, Assad's most strategically important air asset. There are also recurrent videos of heavy artillery and capable anti-tank weapons. And of course we've been offered fairly strong evidence of arms deliveries, perhaps several planeloads, from Croatia.
Despite all this, the FSA has a very difficult time defending its territory and an even more difficult time sustaining offensives. No one suggests that's for lack of numbers, skill or courage. The conclusion seems inescapable - the quality and sophistication of arms supplies tell us nothing about their adequacy without more attention to quantities. But quantities are exactly what can't be ascertained, because videos and journalistic reports can't possibly reveal much about stockpiles throughout Syria. (Imagine trying to determine how often an individual MANPADS appears in videos or reports.) Though analysts may have offered evidence for an impressive the range of weapons, the course of the battle strongly suggests that they're not available in anything like sufficient quantities. Most MANPADS, for example, don't have a particularly high success rate even with trained operators, and acquiring expertise would itself require a large number of firings. There is basically no prospect of the FSA receiving anything like the required quantities through non-state channels. It is equally clear that none of the channels come close to supplying arms and ammunition in strategically important quantities. Other opposition groups are probably in the same position.
So whatever we may hear about current arms supply channels, or about the EU or the US eventually getting around to supplying some unspecified quantity of arms, we have to assume that the supply situation is desperate. Any disruption of current supply channels has to be seen as a very serious matter indeed.