I have no problem with speeding under appropriate circumstances (i.e. I'm doing it myself, in a vehicle I know can handle it, in an area where the traffic and road conditions allow) but situation seems downright scary. Even if the cabbie is a F1 driver, that doesn't compensate for other people on the road who may do stupid things.

Here in CT driving over 85mph on a highway can get one locked up for reckless endangerment. I don't know if there are more stringent rules for cabbies but I'd be pissed if I were you. Def. report the driver before he and/or his passengers and/or another driver become statistics.