That's the best scam. Just say "Oh, ok. Thanks for the ride then!" and get out. It's either a free ride, or the reader magically starts working. They legally have to tell you the reader is broken before the ride. Once I did have a driver try to run my card and it failed multiple times, so I called dispatch and gave them my payment info.

Same thing goes if they don't turn the meter on. Also a free ride. If they don't turn the meter on, ask them to right away. Or, wait until the destination and agree on a reasonable price or simply walk away.

If any cab driver tries to negotiate a flat rate ahead of time, it's usually a rip off. Though, I will do this after a busy event if we can agree on a price that's cheaper than ride share surge pricing and not outrageous. It's gotten so bad that if one does just turn the meter on at a busy event I give them a huge tip and say thank you for not pulling that crap.