Yeah, transport in London barely functioned until oyster cards were introduced! Also, I didn't claim that surveillance was the primary reason for oyster cards,

Yeah, transport in London barely functioned until oyster cards were introduced! Also, I didn't claim that surveillance was the primary reason for oyster cards, but there is no doubt it also functions as an effective large surveillance network. As for other cities, transport isn't as centralised as it is in London so is vastly harder to implement, but for sure others are looking into similar schemes.