They say using a measurement device (like a ruler) is a good way to chastise someone. They do something bad? Chastise them by slapping their wrists, their feet, their eyes, ears, anything! They say something out of turn? CHASTISE THEM!
You're being chastised because you tried to say something in English in とうきょう. Everyone around you slowly turned around, eyes aflame and rulers in hand, ready to chastise you for uttering those forbidden words.