As a youth pastor, we had a group of college age come into our group meeting, yell that a guy with a chainsaw was going crazy with him outside with a real chainsaw. They threw the lights and the next thing he was in the room running through the crowd and I felt warm splatter. I was moving through the crowd to tackle him and take him out, no matter what happened to him, I was going to save as many of my kids as I could. That guy has no idea how tragic his prank could have gone, a chair against his skull could have placed him in a comma the rest of his life. I was not amused. One of our kids had seen her brother, I think it was, shot by a drive by in front of her. She went right back into PSTD and I'll have a hard time ever forgiving those dopes for being so thoughtless and frankly, stupid.
Not to brow-beat, just, For me? Not funny. Apologies for being the downbeat to the thread. Some of us have been that close to real death that a prank that threatens life, even if only in a backpack isn't funny. It is a guy that 1) is hurting another (why it is probably removed from Facebook so quickly as very inappropriate) and 2) potentially, actually, life-threatening for himself, and 3) institutionalizing potentially, for his victim. As soon as it gets to a person who is related to 911 or is a vet, or was at the Boston Marathon, or anybody with any kind of PTSD/anxiety disorder, it goes to horrible and thoughtless for me, very quickly.
People who haven't been this close to the actual thing, don't understand so I have patience and understanding, but I'll try to give my perspective. There are GREAT pranks that hurt nobody that I'd much rather see. These and crass verbal jokes hurt my soul.