Davida Charney pointed out this article on IRBs in the New York Times. The thesis: IRBs are prone to "mission creep" that progressively adds layers of bureaucracy and unreasonable restrictions to research. Money quote: "But to many faculty and graduate students, review boards are like a blister that gets worse with every step. Those outside of the hard sciences say the legitimate concerns over ethics and safety are largely irrelevant to most of their research."
I'm divided. On the one hand, IRBs are definitely encountering mission creep, partially because they like to err on the safe side. On the other hand, despite what the NY Times says, there really are ethical issues even in English studies, and the IRB should have a hand in determining whether human subjects are being treated well.