Yes, Krugman got the Internet wrong. But Andrew Sprung rightly notes how much he has gotten right (at times to my chagrin):

He was right about the Euro. He was right about the Bush tax cuts. He was right about the Iraq war. He was right about the housing bubble. He was right about the size of the stimulus. And, I just accidentally reminded myself, he was right about Obama’s dreams of postpartisanship. On Jan. 28, 2008, with the country in full flush of Obama fever, Krugman posted a warning that Obama ignored for the first 32-odd months of his presidency.