"Nothing clears a room like a grenade through the window fired from 200 yards down the street." Or closer! I find it interesting to note that the RPG and it's many variants like the B-40 have been a bane to our armed forces for almost forty years, and no effective countermeasures still have yet to be introduced by our armed forces. Strange, that.
When we were in Panama, I know of at least one helicopter that went down due to an RPG. In Iraqi Freedom, I think I heard of a few more. I think I read in the early days that one had even been successful in disabling (NOT destroy) an M1A2 Abrams tank. (They came up with counter-measures.)
The RPG is a wicked little weapon and deserves some counter-measure attention AND something similar deserves to be in the hands of our own troops.