Who gets to say when demand based pricing is gouging?

On New Year's Eve in NY I don't think there's anything in the world wrong with increasing the price to the maximum that customers are willing to pay.

The flood is different but I'm not sure where the line gets drawn? Uber already has rates that range from similar (for very specific trips) to drastically more expensive than taxi rates.

Something else not mentioned: incentivizing additional drivers to go out and work during a flood / the aftermath.