Unless you are of the especially anal variety, you probably don't spend your cab rides closely scrutinizing the meter. Perhaps you're distracted by the repetitive offerings of Taxi TV, or maybe you're just concentrating all your efforts on not booting all over the place. Taxi drivers know this, apparently, which is why they've been conning the hell out of you for God knows how many years probably forever.
See, a few weeks ago, one cabbie was fingered by the taxi authorities for repeatedly charging higher out-of-city rates for intra-city trips, to the tune of $40,000 extra dollars. Someone at the Taxi and Limousine Commission probably realized that this couldn't be the only guy pulling this scam. So they undertook a fleetwide review, and the results should make you mildly irate: "35,558 hacks overcharged their passengers at least once," but "about 3,000 drivers were repeat offenders, switching their meters to the higher out-of-city rate on trips within city limits more than 100 times each." Mind you that this is only for a 26-month period analyzed by investigators. There's no reason to believe cabbies haven't been pulling this same ruse since the dawn of time. And it's only because of those mandatory GPS devices that their scheme was uncovered. No wonder they fought so hard against it.