Ten of the least competent time travelers

At io9, Rob Bricken came up with a list of the ten least competent time travelers, including:
Hank Morgan, A Connecticut Yankee in King Arthur's Court

I'm guessing Mark Twain hadn't heard of "the butterfly effect" when he wrote his classic A Connecticut Yankee in King Arthur's Court, because when Hank Morgan wakes up in ancient England, he does the equivalent of murdering every goddamn butterfly