How was that even funny?
If the kid got up at the end, laughing, or even dusting himself off, ok, but this ends with a kid potentially seriously injured. I have no idea how that kid is. And, I don't trust that a parent who would post this at all with their kids in it would only do so if there was no real injury. After all, isn't a trip to the hospital worth 100,000 views on Youtube or likes on Facebook?
Have we actually become that insensitive that we are willing to get a laugh out of a little kid having a full bookshelf fall on him?