Ride-sharing services Uber and Lyft have warned customers they will see inflated rates New Year's Eve and early New Year's Day in response to high demand, a controversial practice known as “surge” pricing. Uber said that some fares will cost more than $100 Wednesday evening and early Thursday, as higher-than-usual demand will far outstrip the supply of drivers.

The company also said it anticipates more than 2 million people to use the service New Year's Eve in what it expects to be the busiest night since the company was founded in March 2009, according to the Los Angeles Times.

Uber's surge pricing, and Lyft's similar “PrimeTime” pricing, has been a highly divisive practice, driving some customers to threaten to never use the services again after being charged ultra-high rates during snowstorms, holidays and other high-traffic times.

Actor Seth Rogen complained about the pricing scheme on Twitter, tweeting earlier that it's "a great way to rip off drunk people. Kind of a brilliant business model” during the backlash against last year's New Year's Eve surge pricing.

But the companies say that they have taken steps to warn people about the potential that they will be charged higher rates, and given advice for when to call an Uber if they want to avoid paying the higher amounts.

“On New Year's Eve, everyone is looking for rides at exactly the same times. We expect the highest demand -- and fares -- between 12:30 a.m. and 2:30 a.m.,” the company said on its website. “For the most affordable rides, request right when the ball drops at midnight or wait until later for prices to return to normal.”

And Uber CEO Travis Kalanick said on Facebook that the company has undertaken “very careful rider messaging around surge pricing, and the perennial angst (and lashings) we get for our aspiration of being 100 percent reliable,” Bloomberg Businessweek reported Wednesday.

Lyft said that to "make sure we have enough drivers on the road on our biggest night of the year, Lyft’s Prime Time limit will be 400 percent, double the usual 200 percent maximum, on New Year’s Eve,” according to Bloomberg Businessweek.

Uber says it plans to donate $1 to Mothers Against Drunk Driving for every ride within the U.S. on New Year's Eve.