By and large, Uber and Lyft are steamrolling government opposition across the U.S.

Last summer in New York, Uber badly embarrassed Mayor Bill de Blasio by soundly defeating his bid to cap the number of for-hire drivers in the city. In the fall, Uber and Lyft beat back the taxi industry in Las Vegas and began offering rides there.

The latest so-called “sharing economy” battleground for the car services is in Austin, Texas, where the two companies are wrangling with the city’s government over fingerprint background checks. On Thursday, the City Council approved the creation of a “public-private partnership” called Thumbs up!, an opt-in program for sharing economy users (“starting with ride-share drivers and riders”) who want to pass a fingerprint background check.

The way Thumbs up! works is like this: Drivers and riders (and ultimately, people on platforms like Airbnb) can go through a fingerprint background check to verify that there isn’t anything like a sexual assault conviction in their history. Drivers would volunteer for the checks instead of the car services, the checks are not mandatory and the city pays for them. But drivers who do opt into the program will be allowed to pick up fares at places like the Austin-Bergstrom International Airport and during events like Austin City Limits and SXSW, where ride-hailing services currently aren’t allowed.

In a phone interview with Re/code on Wednesday night, Austin mayor Steve Adler stressed that Thumbs up! shouldn’t worry Uber and Lyft because it is optional for drivers and “doesn’t punish people for not having something they don’t already have.”

“The reason we’re doing this is because a number of people in the city of Austin have said they’d be safer if they had a driver who had undergone that level background check,” Adler said. “Without regard to whether it’s safer or not, the city council tomorrow is going to demonstrate that people have that option.”

Both Lyft and Uber gave Thumbs up! two thumbs down, characterizing the initiative as a “duplicative” and intrusive measure in separate statements provided to Re/code. You can read both statements at the bottom of this post.

Thumbs up! comes on the heels of an Austin City Council ordinance, passed by a 9-2 vote last month, which mandated that services like Uber and Lyft implement more rigorous, fingerprint-based background checks of their drivers. Uber and Lyft, which say that their business models don’t allow for the time required for such checks, threatened to leave the city should the ordinance come into effect.

The December law was set go live on Feb. 1, but Adler spokesperson Jason Stanford says “the effective date was changed from Feb. 1 to the end of February. The Mayor intends to deal with it and the ballot initiative at the same meeting in February. Therefore, the December initiative will never take effect.”

That initial legislation was prompted by concerns over rider safety, specifically sexual assault. According to a document provided to Re/code, in 2015 the Austin Police Department received 27 reports of unwanted sexual contact in taxi cabs and ride-hailing services. Two took place in an “Independent Ride Share,” five happened in taxis and the remaining 20 occurred during Uber and Lyft rides. Seven assaults were committed by transportation network company drivers.

These numbers, up from eight reports (exclusively in cabs) in 2014, prompted the Police Department and assault victims advocacy organizations to recommend the more stringent background checks for drivers.

Uber and Lyft have exited cities over background check fights in the past. In San Antonio, for example, the two companies left last March after the city passed an ordinance that required city-reviewed background checks. Both Uber and Lyft returned in October, after San Antonio caved and made its program opt-in. It is also worth mentioning that Uber is reportedly experimenting with fingerprint background checks of its own.

By and large, however, ride-hailing services are incredibly popular in Austin. Though Austin law enforcement said fingerprint background checks would be more effective, department chief Art Acevedo voiced concerns at the meeting about the December ordinance, suggesting the disastrous effect Uber’s and Lyft’s exit could have on Austin’s notoriously bad drunk-driving problem.

“We were facing a horrible choice, which is between two safety interests of dealing with drunk-driving and the assault issue,” Adler said. He said that for Thumbs up!, “We redesigned the question, and decided what we were shooting for was to get fingerprinting of ride-share drivers at scale.”

In response to the December ordinance, Uber and Lyft gathered more than 65,000 signatures for a petition to force the City Council to adopt “common sense” ride-hailing rules. If the Council votes down the petition, then the proposal could go to a citywide vote this coming May, similar to what happened with Airbnb and Prop F in San Francisco.

When pressed on whether the city has any leverage over Uber and Lyft, Adler spokesman Jason Stanford reaffirmed Mayor Adler’s concern about the DWI issue.

“We have a horrible drunk driving problem, and arrests have fallen since they’ve gotten here,” Stanford said. “But at the same time, we have other safety concerns that are our responsibility, and the mayor has said he’s not gonna choose between the two.”

Then why not acquiesce to the companies’ demands?

“Because they want to write their own rules,” Stanford said.

Here’s Lyft’s statement on today’s Thumbs up! vote:

“We believe the city council’s action should be guided by the over 65,000 Austinites who trust their voice of disapproval will be heard. Segregating rideshare drivers into different groups, with different economic opportunities – all without any benefit to public safety – hurts drivers, consumers and the City of Austin. The badge proposal on the table makes it harder for the people of Austin to find a safe, reliable and affordable ride.”

And here’s a statement from an Uber spokesperson:

“Austin drivers can currently pick up any rider in any part of the city at any time. Under the ‘incentives program’ passed today, drivers who are not fingerprinted would lose access to the busiest areas of town and major community events. The truth is the ‘badge program’ would penalize drivers who are unable to complete the city’s duplicative background check by revoking their access to critical earning opportunities. It would also leave riders stranded when they most need a ride. Uber continues to oppose it.”