I don't know much about Megan McArdle. I first heard of her when she was ripping the gold standard. Needless to say I wasn't impressed. Now she and Glenn Greenwald have come to fisticuffs. It seems GG accused her of supporting torture, she flipped out in outrage and said he was nuts, and then GG--as is his wont--went back and dug up quotes of her supporting torture.
Don't mess with Glenn.