I see cars with them all the time. On mine the rear brake light on the left is on like the brakes are on. It's somewhat distracting when there's no fog and their tail lights are like that. Makes you think there's something wrong with the brakes for a half second til you realize their fog lights are on. I do have active curve illumination so the left or right fog light comes on when you're turning a corner, but it shuts off afterwards. Same as when you're signaling.
Yeah active curve illumination is everywhere here. But it's a dedicated bulb, not the fog light. Though it sits in the fog light assembly most often. Mine swivels the low beam projector into the turn.