The Syrian army are using these things indiscriminately against the civilian population in the free Syria area
About 20,000 civilians have been killed by these and it has gone largely or almost entirely unreported by the western media as would detract from our now focus against IS
Over time, regime forces have refined their use of the barrel bomb to cause maximum damage - dropping one device and then waiting 10 to 30 minutes to drop another bomb on the same location. According to opposition activists, the aim is to ensure that those who flood the scene to rescue the victims are then themselves killed
We are sitting back and watching this on our pedestal of righteousness as usual
http://en.wikipedia.org/wiki/List_of_Syrian_Civil_War_barrel_bomb_attacks