The Hunley's kill count against it's own side is where the meme part comes from.I have to take exception to the Hunley being on there, nobody involved considered it a superweapon nor anything more than a prototype and experimental proof of concept. Further unlike the others the Hunley actually has a place in the history of the development of military technology considering it was the first submarine to successfully destroy an enemy ship (which that meme underplays by focusing on people killed), something that did not reoccur, AFAIK, until the 1910s in WW1.