Well, this is new. The above video is perhaps the first recorded example purporting to show a Syrian military helicopter downed by rebels using a surface-to-air missile. The insurgents, of course, have been desperate to acquire these weapons in order to counteract the regime's increasing reliance on air power. However, the opposition's international allies have been loathe to provide such missiles, out of fear they could fall into the wrong hands.
The video claims to be filmed in the Aleppo countryside, near to the Sheikh Suleiman military base. A second video appears to show the helicopter crashing to the ground. Sheikh Suleiman has been besieged by the rebels for months, and a rebel commander told the AFP recently that it would fall in "a matter of days."
It's not only SAMs that rebels have gotten their hands on in recent days. Insurgents also overran a military base belonging to the 46th Regiment, near Aleppo, last week. The invaluable Brown Moses blog has a rundown of the equipment seized, which includes tanks, truck-mounted guns, rocket launchers, and long-range artillery. It's possible that the missiles that struck the helicopter at Sheikh Suleiman was also seized from the 46th Regiment's arsenal.
Of course, as the rebels make gains across the country, radical groups are also getting their hands on military equipment. In this video, purportedly filmed in the eastern governorate of Deir Ezzor, members of the jihadist organization Jabhat al-Nusra show off their spoils -- including a tank. While Bashar al-Assad still sits on the throne, these radical groups may be able to make common cause with the broader opposition -- who will control these weapons of war after the regime falls, however, remains an open question.