The message-board 4chan has been rightly blamed for many unsavory Internet things: the celebrity nude scandal, the dangerous “bikini bridge” meme, the brief virality of the self-harm hashtag #cuttingforBieber. Now, the denizens of one of the Internet’s least-principled places are attempting to propagate another tasteless meme: She’s called Ebola-chan, and she’s some cross between a prank, a witles