An old MIT hacker. He placed a bet with a friend that he could visit more locations than any other hacker, and took the sign-in "Sophocles", accompanied by a number indicating how many locations he'd visited before. Sophocles sign-ins have been found numbering well above 1500. Although he might have been prolific, he was not the most creative hacker, and many of his sign-ins have been found in easy-to-access locations. Another hacker, trying to prove that Sophocles was not as impressive as the numbers indicated, took to putting a checkmark over every Sophocles sign-in he found to show that he'd been there too. Today, it is a tradition in the hacking community to "check off" any unchecked Sophocles sign-ins found, and record its location for posterity.