Bowing to their better civic natures, and the pleas of James Foley's family, Twitter and YouTube have pulled down videos and photos of his murder. They had every right to do so, and in my view they did the right thing.
So why am I so uncomfortable with this? Because it's not clear what's too vile to host. And, even more, because Twitter and YouTube are among a tiny group of giant companies with greater and greater power—and less and less accountability—over what we read, hear, and watch online.