I cannot see a small drone bringing down a plane, a plane is going much slower on approach and takeoff and climbs rapidly on takeoff out of the height restrictions.
It's statements like these that really concern me. This is sort of like saying "guns can't kill people, they're too small and people are much bigger". Now, before all the gun advocates get all "up in arms" over this statement, I'm not trying to compare drones and guns. My point is, it's this kind of ignorance that is not going to go well for our "drone" community. I've said it before and I'll say it again. We have to be knowledgable about our craft. We need to know what it's capable of doing, both good and bad. We need to be aware of where we fly, when we fly, and who or what might be impacted should an accident occur. It all seems pretty reasonable to me.
Now, for your reading pleasure. Enjoy
http://gizmodo.com/5989318/what-happens-when-a-drone-hits-a-plane