Who is Paul McCartney? In less than 140 characters, troves of Twitterers are digging themselves into holes by posing that question. In response to the musician's performance at the Grammys Sunday night, many an ignorant and shameful twitterer had to inquire who the former Beatles band member was.

This situation is similar, though significantly worse, to the Arcade Fire debacle at the 2011 Grammys and this year's confusion over Bonny Bear (Bon Iver).